Troubleshooting DriveSpace in Windows 95

ID: Q133175

The information in this article applies to:

Microsoft Windows 95
Microsoft Plus! for Windows 95
Microsoft Windows 95 OEM Service Release version 2

This article describes troubleshooting steps that may help you solve problems with DriveSpace in Windows 95. This information is also available in our Windows 95 DriveSpace Troubleshooting Wizard. We recommend using this wizard, but we have also created this text-based article for your convenience. The Windows 95 DriveSpace Troubleshooting Wizard is located on:

http://support.microsoft.com/support/tshoot/default.asp

SUMMARY

This article describes how to troubleshoot the following problems with DriveSpace in Windows 95:

DriveSpace displays an error message

Your computer stops responding (hangs) during compression

Your computer does not boot properly after compressing a drive

MORE INFORMATION

DriveSpace Displays an Error Message

If you receive an error message while running DriveSpace, check the Microsoft Knowledge Base for existing articles about that error message. Some of the most common errors are:

Q124558 DriveSpace Err Msg: Mini.cab File Is Missing or Damaged...

Q132883 Err Msg: Drive C Contains Errors That Must Be Corrected...

Q123441 Windows 95 DriveSpace Err Msg: Windows Cannot Perform...

Q154839 Err Msg: Windows Has Detected a Compressed Drive Access Error

Q134859 DriveSpace VxD and Real-Mode Driver Are Mismatched

Q142919 Error Message: ID Number DRVSPACE125

Q155689 Error Message: Mini.cab Is Missing or Corrupt

Computer Hangs During Compression

If your computer hangs while DriveSpace is running, follow these steps:

If DriveSpace stops when it is 25 percent finished, see the following article in the Microsoft Knowledge Base:
Q136830 DriveSpace May Fail to Start in Mini-Windows Mode

If DriveSpace stops when it is between 25 and 100 percent finished, see the following article in the Microsoft Knowledge Base:
Q136899 DriveSpace Restartability in Windows 95 and MS Plus!

If DriveSpace stops while you are uncompressing or resizing a compressed drive, follow these steps:
1. Start your computer with your Windows 95 or Microsoft Plus! Startup disk. When you see the "Starting Windows 95" message, press the F8 key, and then choose Step-By-Step Confirmation from the Startup menu. Press N when you are prompted to load the DoubleSpace or DriveSpace driver.
  
  NOTE: If you did not create a Startup disk during Windows 95 Setup, or you did not update your Startup disk during Microsoft Plus! Setup, you can create a Startup disk manually.
  
  For information about creating or updating a Startup disk, please see the following articles in the Microsoft Knowledge Base:
  Q138991 Problems Using Windows 95 or Microsoft Plus! Startup Disk
  
  Q136900 Manually Updating the Startup Disk After Installing Microsoft Plus!
  IMPORTANT: If your computer uses software that translates disk geometry (such as OnTrack Disk Manager or Micro House EZ-Drive), make sure to load the translation software when you start your computer with the Startup disk.
2. Verify that you have the correct DriveSpace and ScanDisk files on drives A and C.
  
  Check the Startup disk for the correct Drvspace.bin and Scandisk.exe files with the following commands:
  dir /a a:\drvspace.bin
  dir a:\scandisk.exe
  NOTE: The Startup disk does not contain a Dblspace.bin file. The Drvspace.bin file should have the file size and date noted below, depending on whether or not Microsoft Plus! is installed. If you did not install Microsoft Plus!, the Scandisk.exe file should be 134,738 bytes in size. If you installed Microsoft Plus!, the Scandisk.exe file should be 137,836 bytes in size.
  
  If you do not have the correct versions of these files, extract new copies from your original disks or CD-ROM to the root folder of drive A.
  
  For information about using the Extract tool, please see the following article in the Microsoft Knowledge Base:
  Q129605 How to Extract Original Compressed Windows Files
  Make sure that both the Drvspace.bin and Dblspace.bin files exist in the root folder of drive C. To check for these files, type the following command:
  dir /a c:\d??space.bin
  If you did not install Microsoft Plus!, you should see the following files:
```
         File name      Date/Time            Size
         ------------------------------------------
         Drvspace.bin   07-11-95 9:50 A.M.   71,287
         Dblspace.bin   07-11-95 9:50 A.M.   71,287 
```
  If you did install Microsoft Plus!, you should see the following files:
```
         File name      Date/Time             Size
         -------------------------------------------
         Drvspace.bin   07-14-95 12:00 A.M.   64,135
         Dblspace.bin   07-14-95 12:00 A.M.   64,135 
```
  If you are using Windows 95 OEM Service Release 2, you should have the following files whether or not Microsoft Plus! is installed:
```
         File name      Date/Time             Size
         -------------------------------------------
         Drvspace.bin   08-24-96 11:11 A.M.   65,271
         Dblspace.bin   08-24-96 11:11 A.M.   65,271 
```
  IMPORTANT: Drvspace.bin and Dblspace.bin are the same files with different names. Copy the Drvspace.bin file to Dblspace.bin on the Startup disk with the following commands before you proceed:
  attrib -s -h -r a:\drvspace.bin
  copy a:\drvspace.bin a:\dblspace.bin
  attrib +s +h +r a:\d??space.bin
3. Make sure that either a Drvspace.ini or Dblspace.ini file exists in the root folder of drive C. To check, type the following command:
  dir /a c:\d??space.ini
4. If neither a Drvspace.ini or Dblspace.ini file exists on the hard disk, create one using the EDIT command from the Startup disk. To do this, type edit c:\drvspace.ini and then press ENTER. Then, close the editor.
5. Restart your computer and do not press the F8 key. The computer should boot into Windows 95 and the contents of the compressed drive should be available.
  
  Check for a Restart.drv file in the root folder of drive C or its host drive by typing the following command:
  dir /a <drive>:\restart.drv
  This file is required by DriveSpace to restart a failed operation. If the Restart.drv file exists, copy the Config.pss and Autoexec.pss files from the Failsafe.drv folder to the root folder of the physical boot drive by typing the following commands at a command prompt:
  copy <drive>:\failsafe.drv\config.pss <drive>:\config.sys
  copy <drive>:\failsafe.drv\autoexec.pss <drive>:\autoexec.bat
  Then, edit the Drvspace.ini or Dblspace.ini file and place a semicolon (;) before the "ActivateDrive" line for compressed drive C (if it is being mounted). For example,
  ;ActivateDrive=H,C0
  This causes the computer to boot to the physical boot drive containing the Failsafe.drv folder and the Restart.drv file.
  
  NOTE: If there are multiple "ActivateDrive" lines that reference drive C, place the semicolon before the line that ends with "C0." The Drvspace.ini file is a hidden, system, read-only file stored in the root folder of the physical boot drive. To edit the file you must first remove the Hidden, System, and Read-Only attributes. To do so, type the following line at a command prompt:
  attrib -s -h -r <drive>:\d??space.ini
  Restart your computer and DriveSpace should try to complete the failed operation in mini-Windows mode.
6. If the Restart.drv file does not exist, DriveSpace cannot restart the failed operation automatically. Format the drive and restore data from a recent backup, or contact Microsoft Technical Support for additional assistance.
  
  NOTE: It may be impossible to recover data at this point. It may be necessary to format the drive and restore from a recent backup or to reinstall Windows 95.

If you are troubleshooting a problem with one of the following DriveSpace operations that was not completed successfully, these operations can be continued after the underlying problems are resolved (provided you have not made manual changes to the DriveSpace configuration, such as changing an .ini file setting or renaming a CVF):
- Compressing an existing drive
- Uncompressing a DoubleSpace or DriveSpace drive
- Creating a new, empty DriveSpace drive
- Changing the size of a DoubleSpace or DriveSpace drive
- Changing the estimated compression ratio (ECR) for a DoubleSpace or DriveSpace drive
- Mounting a DoubleSpace or DriveSpace drive
- Upgrading (converting) a DoubleSpace or DriveSpace drive to DriveSpace 3

If you are not troubleshooting a problem with one of the DriveSpace operations listed above, verify that the compressed drive is mounted by trying to access the drive letter that was created when you originally compressed the drive.

For example, if you compressed drive C and DriveSpace created drive letter H for the host drive, type h: and press ENTER. If you receive an "Invalid drive specification" error message, the compressed drive is not mounted.

Use ScanDisk to repair or mount the unmounted CVF. To do so, type the following line:
scandisk <drive>:
where <drive> is the letter of the compressed drive if it was mounted in step 5, or type
Scandisk /mount=<YYY><drive>
where <YYY> is the extension of the unmounted CVF and <drive> is the drive containing the CVF.

When you are prompted to check the host drive first, do so. Perform a surface scan on all drives, and fix any errors found.

If you receive an error message stating that you cannot use compressed drive C because it is not mounted, restart your computer and then repeat step 5.

NOTE: If there is insufficient memory available for ScanDisk to check the compressed drive, repeat the command after modifying your Startup disk to load the compression driver in upper memory. To do so, create a Config.sys file on the Startup disk that includes at least the following commands
dos=umb
device=<drive>:\failsafe.drv\windows\himem.sys
device=<drive>:\failsafe.drv\windows\emm386.exe noems
devicehigh=<drive>:\failsafe.drv\command\drvspace.sys /move
where <drive> is either drive C or its host drive. The Failsafe.drv folder is a hidden folder on the physical boot drive that is used by DriveSpace to restart interrupted disk compression operations. This folder should be available even if your compressed drive is not mounted.

The Failsafe.drv folder may also contain a Config.emm file that can be used to optimize conventional memory. However, you must change the drive letter designation on the "device=" and "devicehigh=" lines to reference the host for drive C if drive C is a compressed drive that is mounted when you boot with the Startup disk.

IMPORTANT: If your hardware configuration requires upper memory to be excluded when using Emm386.exe, include the appropriate "x=mmmm-nnnn" syntax on the Emm386.exe command line.

Scan your computer for viruses using the latest anti-virus software available to you. If you upgraded from Microsoft MS-DOS 6.0 or later and you have Microsoft Anti-Virus for MS-DOS installed, run Msav.exe to detect and clean all logical drives.

WARNING: The presence of a computer virus may lead to partial or complete data loss when you perform the following troubleshooting steps. For additional information about computer viruses, please see the following article in the Microsoft Knowledge Base:
Q129972 Description of Computer Viruses

Perform a thorough surface scan on your hard disk. To do so, follow these steps:
1. Edit the Scandisk.ini file on the Startup disk to include the following lines:
  [Environment] ScanTimeOut=On NumPasses=5
2. Save and close the Scandisk.ini file.
3. Type the following line to scan the hard disk
  scandisk <drive>:
  where <drive> is the compressed drive, if it is mounted. If the compressed drive is not mounted, use the host drive letter instead. Note that the host drive letter is the same as the drive letter you normally use for the compressed drive (when you are not having a problem with the compressed drive).
  
  When you are prompted, instruct ScanDisk to perform the following actions:
  - check the host drive first
  - mount any unmounted CVFs
  - perform a surface scan on both drives
  - fix all errors found
  - view, and save, a log file
  NOTE: This procedure may take some time, particularly if you have a large hard disk or more than one hard disk. To automate this procedure so that ScanDisk does not prompt you for instructions, include the following lines in the Scandisk.ini file:
```
         [Environment]
         LfnCheck      = Off
         Mount         = Always

         [Custom]
         DriveSummary  = Off
         AllSummary    = Auto
         Surface       = Always
         CheckHost     = Always
         SaveLog       = Overwrite
         Undo          = Never

         DS_Header     = Fix
         FAT_Media     = Fix
         Okay_Entries  = Fix
         Bad_Chain     = Fix
         Crosslinks    = Fix

         Boot_Sector   = Fix
         Invalid_MDFAT = Fix
         DS_Crosslinks = Fix
         DS_LostClust  = Fix
         DS_Signatures = Fix
         Mismatch_FAT  = Fix
         Bad_Clusters  = Fix
         Bad_Entries   = Delete
         LostClust     = Save 
```
  Then, run ScanDisk using the following command:
  scandisk <drive>: /custom
  ScanDisk creates a Scandisk.log file that you can examine to determine whether ScanDisk fixed any problems on the drive. The problem should now be resolved unless you are troubleshooting a failed DriveSpace operation that is restartable. If this is not the case, you may want to review the troubleshooting steps.

Your Computer Does Not Boot Properly After Compressing a Drive

A compressed drive may not be mounting correctly. To troubleshoot this problem, follow steps 5-8 above.

If the compressed drive is mounted correctly but Windows 95 still does not load, see the following article in the Microsoft Knowledge Base:

Q136337 Troubleshooting Windows 95 Startup Problems and Error Messages

Keywords : kbtool kbtshoot drvspace win95
Version : WINDOWS:95
Platform : WINDOWS
Issue type : kbhowto