Last Modified: 5/23/98 ( 640x480 256 Color )
Solutions and Trouble Shooting Techniques when:
Safe Mode will NOT startup
Safe Mode WILL startup
SHUTDOWN does NOT complete
DETAILS of Win95 BOOT
Startup Problems:
WINDOWS 95 STARTUP PROBLEMS ??
Safe Mode will NOT Start:
(1) Will the computer boot in Safe mode?
(2) Have you scanned your computer for a virus?
Get a virus-scanning program and scan your
hard disk for any signs of infection.
If you computer has a virus, you should take the
appropriate actions to remove
it, and then see if you still have startup
problems.
(3) Are you using overlay software?
Are you using overlay software on your
hard disk controller? If so, is it
configured correctly? Consult your overlay
software documentation for
information about the proper
configuration.
(4) Is the hard disk damaged?
The hard disk may be damaged. If you can boot to a
Safe-mode command
prompt, try running ScanDisk to see if
any errors are detected.
If NONE of the above have solved your problem, then the odds are, at this point you will need to RELOAD your Operating System from scratch. Don't forget to copy off your CD-ROM drivers and related files and directories found in your CONFIG.SYS and AUTOEXEC.BAT files. You'd be well served to copy your CONFIG.SYS and AUTOEXEC.BAT to a floppy as well in ANY case.
Safe Mode WILL Start:
(1) Is there a conflict in the Config.sys or Autoexec.bat file?
When you see the "Starting Windows 95"
message, press the F8 key. From the
Startup menu, choose Step-By-Step Confirmation. Step
through each command
in the Config.sys and Autoexec.Bat files. Load only
one line and see if the
computer starts. If so, restart the computer and load
two lines. Continue until the
startup problem returns. Once you have determined
which line is causing the
problem, check the syntax of that line, or contact
the manufacturer of the program
that is being run for more assistance.
(2) Are the protected-mode drivers configured incorrectly or
damaged?
To determine whether a protected-mode driver is preventing the computer from
booting properly, follow these steps:
1.Start Windows 95 in Safe mode.
2.Use the right mouse button to click My Computer, and then click
Properties on the menu that appears.
3.On the Device Manager tab, disable any devices in the following
categories: Display adapters Floppy disk controllers Hard disk controllers
Keyboard Mouse Network adapters PCMCIA socket Ports SCSI
controllers Sound, video, and game controllers To disable a device,
follow these steps: a. In Device Manager, double-click the category name,
and then double- click the device. b. On the General tab, click the Original
Configuration (Current) check box to clear it, and then click OK. c. Restart
your computer.
4.Once Windows 95 restarts, enable the devices you disabled in step 3.
Enable the devices in the following order:
Com ports
Hard disk controllers
Floppy disk controllers
Other devices
To enable a device, follow these steps: a. In Device Manager,
double-click the category name, and then double- click the device. b. On
the General tab, click the Original Configuration (Current) check box to
select it, and then click OK. c. While the properties for each device are
open, click the Resources tab and make sure there are no conflicts listed
in the Conflicting Devices list.
5.Restart your computer.
If the computer does not boot, restart the computer in Safe mode and disable the
last device you enabled. This driver or device may be configured incorrectly or
may be damaged. Consult your device documentation for more information.
(3) Are programs being loaded from the Startup group?
If programs are being loaded from the Startup group, remove them one at a time
and restart the computer to isolate the problem program. For information about
modifying the Startup group, see the Windows 95 Help.
(4) Is your video adapter or driver compatible and working properly?
If the computer will boot in Safe mode, change your video display driver to the
Windows 95 Standard VGA driver. To do this, follow these steps:
1.In Control Panel, double-click Display.
2.Click the Settings tab, and then click Change Display Type.
3.Click the Change button in the Adapter Type section, and then click
Show All Devices.
4.In the Manufacturers box, click (Standard Display Types).
5.In the Models box, click Standard Display Adapter (VGA), click OK, and
then click Close.
6.Click Close.
If the computer will not boot in Safe mode, or these steps do not work properly,
your display adapter may not be configured correctly or may be damanged.
Check your display adapter documentation to ensure it is configured and
installed correctly.
(5) Is the registry damaged?
1.Boot to a command prompt.
2.Type the following line to remove the file attributes from the registry
backup: c:\windows\command\attrib -h -s -r c:\system.1st
3.Remove the file attributes from the current registry by typing:
c:\windows\command\attrib -h -s -r c:\windows\system.dat
4.Rename the current registry by typing: ren c:\windows\system.dat *.dax
5.Copy the backup file to the current registry by typing: copy c:\system.1st
c:\windows\system.dat
6.Restart your computer.
NOTE: The System.1st file is a backup of the registry created during the final
stage of Windows 95 Setup. Therefore, the "Running Windows 95 for the first
time" banner is displayed and Windows 95 finalizes settings as if it were being
installed. If replacing the System.dat file with the System.1st file resolves the
issue, the problem may be related to registry damage. Programs and device
drivers added after Windows 95 was installed may require reinstallation to
update the new registry. If the issue is not resolved, restore the original registry.
To do so, follow these steps:
1.Restart the computer to a command prompt.
2.Type the following lines: c:\windows\command\attrib -s -h -r
c:\windows\system.dat copy c:\windows\system.dax
c:\windows\system.dat
3.Restart the computer.
(6) Are the entries in the Windows .ini files correct?
To determine whether the System.ini or Win.ini file is causing a problem, try the
following steps:
1.Rename the System.ini file in the Windows folder to System.sav.
2.Copy (do not rename) the System.cb file in the Windows folder to
System.ini.
3.Add the following line to the [boot] section of the System.ini file and then
save the file: drivers=mmsystem.dll
4.Rename the Win.ini file in the Windows folder to Win.sav.
5.Restart your computer.
If this works, there is a problem with an entry in the System.ini or Win.ini file.
Examine these files more closely to determine the exact cause of the problem.
(7) Is there a Winstart.bat file loading TSRs for your older
Windows-based programs?
A Winstart.bat file may be located in your Windows folder. If it exists, rename it
to Winstart.old. If this resolves the problem, one of the files being loaded by the
Winstart.bat file is causing the problem. Contact the manufacturer of the program
that is causing the problem for information about using it with Windows 95.
If NONE of the above have solved your problem, then the odds are, at this point
you will need to RELOAD your Operating System from scratch. Don't forget to copy
off your CD-ROM drivers and related files and directories found in your CONFIG.SYS and
AUTOEXEC.BAT files. You'd be well served to copy your CONFIG.SYS and AUTOEXEC.BAT to
a floppy as well in ANY case.
< back to TOP >
Shutdown Problems:
WINDOWS 95 SHUTDOWN PROBLEMS ??
(1) Check your computer's CMOS settings.
Check your computer's CMOS settings to make sure they are correct. (You may
need to contact the computer manufacturer to verify these settings.)
(2) Is there a memory conflict in the upper memory area?
To determine if the problem is being caused by a memory conflict that still exists
when Emm386.exe is not loaded from the Config.sys file, follow these steps:
1.Click the Start button, click Run, type "sysedit" (without quotation
marks) in the Open box, and then click OK.
2.Click the Config.sys window.
3.In the Config.sys file, make sure the following lines exist in this order:
device=c:\windows\himem.sys device=c:\windows\emm386.exe
noems x=a000-f7ff
4.Save the Config.sys file, and then exit System Configuration Editor.
5.Restart the computer, then shut down Windows 95 and wait for Windows
95 to shut down.
If Windows 95 shuts down properly, the problem may be caused by a memory
conflict that still exists when Emm386.exe is not loaded from the Config.sys file.
For information about determining the exact location of the memory conflict,
please see the following article in the Microsoft Knowledge Base: Locating and
Excluding RAM/ROM Addresses in the UMA (Q112816)
(3) Are the entries in the Windows .ini files correct?
To determine whether the System.ini or Win.ini file is causing a problem, try the
following steps:
1.Rename the System.ini file in the Windows folder to System.sav.
2.Copy (do not rename) the System.cb file in the Windows folder to
System.ini.
3.Add the following line to the [boot] section of the System.ini file and then
save the file: drivers=mmsystem.dll
4.Rename the Win.ini file in the Windows folder to Win.sav.
5.Restart your computer.
If this works, there is a problem with an entry in the System.ini or Win.ini file.
Examine these files more closely to determine the exact cause of the problem.
(4) Is the Advanced Power Management feature on your computer
causing the shutdown problem?
To determine if Advanced Power Management (APM) is causing the shutdown
problem, disable it by following these steps.
Note: Not all computers have APM features. If your computer does not
have APM features, continue with the troubleshooter.
1.In Control Panel, double-click System, and then click the Device Manager
tab.
2.Double-click the System Devices branch to expand it.
3.Double-click Advanced Power Management in the device list, click the
Settings tab, and then click the Enable Power Management check box to
clear it.
4.Click OK until you return to Control Panel.
5.Restart Windows 95.
6.Shut down Windows 95. Wait for Windows 95 to shut down.
If Windows 95 shuts down properly, the problem may be caused by APM.
Contact the computer's manufacturer for assistance.
(5) To determine if the shutdown problem is caused by the Windows 95 file system
settings, follow these steps:
1.In Control Panel, double-click System, and then click the Performance tab.
2.Click File System, and then click the Troubleshooting tab.
3.Click all the check boxes to select them.
4.Click OK, click Close, and then click Yes.
5.Restart Windows 95.
6.Shut down Windows 95. Wait for Windows 95 to shut down.
If Windows 95 shuts down properly, the problem may be related to the file
system settings. To better determine which file system setting is causing the
problem, follow the steps above but clear the check box for one option.
If Windows 95 shuts down properly, repeat the steps again and clear the
check box
for another option. Repeat this process until you determine which file system
setting is causing the problem. For more information about the file system
Troubleshooting tab, please see the following article in the Microsoft Knowledge
Base: Description of the File System Troubleshooting Settings (Q165503)
(6) Is the problem listed in the Bootlog.txt file?
View the Bootlog.txt file to pinpoint the problem. If Windows 95 still hangs
during the shutdown process, examine the Bootlog.txt file for "Terminate="
entries. These entries are located at the end of the file and may provide clues as
to the cause of the problem. Each "Terminate=" entry should have a matching
"EndTerminate=" entry on a successful shutdown. If the last line in the
Bootlog.txt file is "EndTerminate=KERNEL," Windows 95 shut down
successfully. If the last line in the Bootlog.txt file is one of the following entries,
check the listed possible cause:
Terminate=Query Drivers
Possible memory manager issue (such as
QEMM).
Terminate=Unload Network
Possible conflict with real-mode network
driver in the Config.sys file.
Terminate=Reset Display
Disable video shadowing. You may also
need an updated video driver.
Terminate=RIT
Possible timer-related problems with the
sound card or an old mouse driver.
Terminate=Win32
Problem with a 32-bit program blocking a
thread. Possibly Microsoft Visual C for
Windows.
(7) Is the exit sound file causing problems with shutdown?
To determine if the shutdown problem is being caused by a damaged exit sound
file, follow these steps:
1.In Control Panel, double-click Sounds.
2.In the Events box, click Exit Windows.
3.In the Name box, click None.
4.Click OK.
5.Shut down Windows 95. Wait for Windows 95 to shut down.
If Windows 95 does not hang during the shutdown process, the problem may be
caused by a damaged exit sound file. Restore the sound file from a backup, or
reinstall the program that provided the sound file. If NONE of the above have solved
your problem, then the odds are, at this point you will need to RELOAD your Operating
System from scratch. Don't forget to copy off your CD-ROM drivers and related files
and directories found in your CONFIG.SYS and AUTOEXEC.BAT files. You'd be well
served to copy your CONFIG.SYS and AUTOEXEC.BAT to a floppy as well in ANY case.
The Windows 95 startup process can be broken into the following steps:
The read-only memory (ROM) Basic Input-Output (BIOS) bootstrap process
The master boot record (MBR) and boot sector
The Io.sys file
Real-mode configuration
The Win.com file and the Windows 95 Environment
Step 1 - The ROM BIOS Bootstrap Process
When you start your computer, the ROM BIOS bootstrap loads from the FFFF0h memory address. The following steps occur during the ROM BIOS bootstrap process:
The Power On Self-Test (POST) occurs.
The A drive is checked for the existence of a boot disk.
If a boot disk is not found in the A drive, the ROM BIOS bootstrap checks for a hard disk. If a hard disk is found, the ROM loader transfers control to the operating system loader.
The master boot record and partition table are read.
Microsoft and several original equipment manufacturers (OEMs) have defined a Plug and Play BIOS specification. This specification defines the interactions between the Plug and Play BIOS, Plug and Play devices, and option ROMs. If your computer has a Plug and Play BIOS, the following additional steps are performed:
The Plug and Play BIOS checks non-volatile random access memory (RAM) for input/output (I/O) port addresses, interrupt request lines (IRQs), direct memory access (DMA) channels, and other settings needed to configure Plug and Play devices on the computer.
All Plug and Play devices found by the Plug and Play BIOS are disabled.
A map of used and unused resources is created.
The Plug and Play devices are configured and re-enabled, one at a time.
Windows 95 Configuration Manager queries the Plug and Play BIOS for device information, and then queries each Plug and Play device for its configuration.
If your computer does not have a Plug and Play BIOS, Plug and Play devices are initialized using their default settings when you start your computer. These devices may be reconfigured dynamically when Windows 95 starts.
Step 2 - The Master Boot Record and Boot Sector -----------------------------------------------
The master boot record determines the location of the boot partition by reading the partition table located at the end of the master boot record. Once the location of the boot partition is determined, the master boot record passes control to the boot sector in that partition. The boot sector contains the disk boot program and a table of disk characteristics. The boot sector checks the BIOS Parameter Block (BPB) to find the location of the root directory, and then copies the Io.sys file from the root directory into memory.
Step 3 - The Io.sys File
The following steps occur when the Io.sys file loads into memory:
A minimal file allocation table (FAT) file system is loaded.
The Msdos.sys file is read.
The "Starting Windows 95" message is displayed for <n> seconds, or until you press a Windows 95 function key. The amount of time the message is displayed is determined by the BootDelay=<n> line in the Msdos.sys file. The default is 2 seconds.
If you have multiple hardware profiles in Windows 95, you receive the following message and must choose a hardware configuration to use:
Windows cannot determine what configuration your computer is in.
The Logo.sys file is loaded and displays a startup image on the screen.
If the Drvspace.ini or Dblspace.ini file exists, the Drvspace.bin or Dblspace.bin file is loaded into memory.
The Io.sys file checks the system registry files (System.dat and User.day) for valid data.
The Io.sys file opens the System.dat file. If the System.dat file is not found, the System.da0 file is used for startup. If Windows 95 starts sucessfully, the System.da0 file is copied to the System.dat file.
The Dblbuff.sys file is loaded if the "DoubleBuffer=1" is in the Msdos.sys file, or if double buffering is enabled under the following registry key:
HKLM\System\CurrentControlSet\Control\WinBoot\DoubleBuffer
Windows 95 Setup automatically enables double buffering if it detects that it is required.
If you have multiple hardware profiles in Windows 95, the hardware
profile you chose is loaded from the registry.
The Io.sys file processes the Config.sys file.
Step 4 - Real-Mode Configuration
Some hardware devices and programs require that drivers or files be loaded in real-mode in order for them to work properly. To ensure backwards compatibility with these types of hardware devices or programs, Windows 95 processes the Config.sys and Autoexec.bat files if they exist.
The Config.sys file loads drivers into memory. If the Config.sys file does not exist, the Io.sys file loads the following required drivers:
- Ifshlp.sys
- Himem.sys
- Setver.exe
The Io.sys file obtains the location of these files from the "WinBootDir=" line of the Msdos.sys file. These files must reside on the hard disk.
Windows 95 reserves all global upper memory blocks (UMBs) for Windows 95 operating system use or for expanded memory support (EMS).
The Autoexec.bat file loads files and terminate and stay resident (TSR) programs into memory.
Step 5 - The Win.com File and the Windows 95 Environment
After the Autoexec.bat file is processed, the Win.com file is run.
The Win.com file accesses the Vmm32.vxd file. If there is enough available RAM, the Vmm32.vxd file loads into memory, otherwise, it is accessed from the hard disk. This may result in a slower startup time. The Vmm32.vxd file is similar to the Win386.exe file used in earlier versions of Windows.
The real-mode virtual device driver loader checks for duplicate virtual device drivers (VxDs) in the Windows\System\Vmm32 folder and the Vmm32.vxd file. If a VxD exists in both the Windows\System\Vmm32 folder and the Vmm32.vxd file, the duplicate VxD is "marked" in the Vmm32.vxd file so that it is not loaded.
Real-mode VxDs can be loaded into memory in any of the following ways:
- Real-mode device drivers or TSRs that respond to the Windows 95
INT2F broadcast load their embedded VxDs when Windows 95 starts.
- Drivers internal to the Vmm32.vxd file that are not "marked" are
loaded from the following registry key:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VxD
If the real-mode virtual device driver loader finds a "marked"
driver, it changes its registry entry from a VxD (a driver preceded
with an asterix "*") to a file with a .vxd extension so that the
external driver is found in the Windows\System\Vmm32 folder. When
the external driver is found, it is loaded into memory.
- VxDs that are not already loaded by the Vmm32.vxd file are loaded
from the [386 Enh] section of the Windows\System.ini file.
- Some VxDs are required for Windows 95 to run properly. These
required VxDs are loaded automatically and do not require a registry
entry. The following VxDs are required by Windows 95:
*BIOSXLAT *CONFIGMG *DYNAPAGE
*DOSMGR *EBIOS *IFSMGR
*INT13 *IOS *PAGESWAP
*SHELL *V86MMGR *VCD
*VCACHE *VCOMM *VCOND
*VDD *VDMAD *VFAT
*VKD *VMCPD *VPICD
*VTD *VTDAPI *VWIN32
*VXDLDR
The real-mode virtual device driver loader checks that all required VxDs loaded sucessfully. If not, it attempts to load the drivers again.
Once the real-mode virtual device driver loading is logged, driver initialization occurs. If there are any VxDs that require real-mode initialization, they begin their process in real-mode.
Vmm32 switches the computer's processor from real-mode to protected- mode.
A three-phase VxD initialization process occurs in which the drivers are loaded according to their InitDevice instead of the order in which they are loaded into memory. The VxDs are carried out in the following sequence:
a. SYS_CRITICAL_INIT (SYSCRITINIT):
Interrupts are disabled during this phase. This gives VxDs time to prepare for device initialization without being interrupted by the system. No file I/O is allowed during SYSCRITINIT, so all SYSCRITINITs are not written to the Bootlog.txt file until after SYSCRITINIT is complete for all VxDs.
b. SYS_DEVICE_INIT (DEVICEINIT)
The bulk of the VxD initialization takes place during this phase. File I/O is allowed during DEVICEINIT, so each VxD's DEVICEINIT is logged as it occurs. The one exception is during Ifsmgr's DEVICEINIT. Ifsmgr takes over the real-mode file system, and disk I/O is not allowed until Ifsmgr's DEVICEINIT succeeds. For this reason, Ifsmgr does not appear in the DEVICEINIT phase.
When a DevLoader VxD is called, it loads other drivers it is responsible for, regardless of their InitDevice order. The DevLoader examines the Registry and finds drivers (for example, portdrivers [such as.mpd files]) and any associated support drivers. It then initializes the device associated with these drivers. During this phase, if a VxD failed to initialize, it was unable to properly communicate with the hardware or service it drives. Typically, this is due to incorrect hardware settings or the service not being installed.
The remaining static VxDs continue with the initialization phase. Also, dynamic VxDs may begin initializing during this phase. They do not have a SYSCRITINIT phase. However, a dynamic VxD may also load anytime after Windows 95 has started.
c. SYS_INIT_COMPLETE (INITCOMPLETE)
VxDs that successfully pass the InitComplete phase should be working properly. If a VxD was listed in one of the previous phases but is not successful in this phase, that VxD is unloaded from memory.
GUI Components:
After all the static VxDs are loaded, the Krnl32.dll, Gdi.exe, User.exe, and Explorer.exe (the default Windows 95 shell) files are loaded.
Network Environment and Multi-User Profiles:
The next step in the startup process is to load the network environment. Once this occurs, the user is prompted to log on to the network that is installed.
Windows 95 allows multiple users to save their custom desktop settings. When a user logs on to Windows 95, their desktop settings are loaded from the registry. If the user does not log on, the desktop configuration uses a default desktop.
StartUp Group and RunOnce Programs:
Programs in the StartUp group and the RunOnce registry key are run during the last phase of the startup process. After each program in the RunOnce registry key is started, the program is removed from the key.
END of DETAILS