Cannot Start Computer After Running DriveSpace on IBM Computer

• Microsoft Windows 95
• Microsoft Plus! for Windows 95

SYMPTOMS

When you use DriveSpace to compress a drive on an IBM Aptiva or PS/1 computer, you may receive the following message when you start your computer after the compression process is finished or when DriveSpace restarts your computer during the compression process:

   Windows has disabled direct disk access to protect your long file-
   names. To override this protection, see the LOCK /? command for more
   information.

   The system has been halted. Press CTRL+ALT+DEL to restart your
   computer.

CAUSE

This problem can occur when you are running Ps1pfile.exe from your Autoexec.bat file. This program attempts to bypass the operating system and system ROM BIOS and write to the hard disk directly. When programs attempt to access the hard disk in this manner, Windows 95 prevents the program from doing so and displays the message.

RESOLUTION

To work around this problem, use one of the following methods:

• If the message is displayed when you attempt to start your computer after the compression process is finished, configure your computer so that Ps1pfile.exe is allowed to write to all hard disks on your computer directly. To do so, follow these steps:

  1. Start Windows 95 in Safe mode and then use any text editor (such as

        Notepad) to open the Autoexec.bat file.
  

  2. Before the line that contains Ps1pfile.exe, insert a line similar to

        the following for each hard disk on your computer
  

           echo y | lock <drive>:\ > nul
  
        where <drive> is the hard disk letter. For example, if your computer
        contains drive C and drive H, insert the following lines before the
        line that contains Ps1pfile.exe:
  
           echo y | lock c:\ > nul
           echo y | lock h:\ > nul
  
        Note that lines for the hard disks on your computer may already
        exist in the file. To determine which hard disks currently exist on
        your computer, run DriveSpace and view the physical drives,
        compressed drives, and host drives that appear in the list of
        drives. To run DriveSpace, click the Start button, point to
        Programs, point to Accessories, point to System Tools, and then
        click DriveSpace.
  
     3. After the line that contains Ps1pfile.exe, insert a line similar to
        the following for each hard disk on your computer
  
           unlock <drive>: > nul
  
        where <drive> is the hard disk letter. For example, if your computer
        contains drive C and drive H, insert the following lines after the
        line that contains Ps1pfile.exe:
  
           unlock c: > nul
           unlock h: > nul
  
        Note that lines for the hard disks on your computer may already
        exist in the file.
  
     4. Save and then close the Autoexec.bat file.
  
     5. Restart your computer.
  
  

• If the message is displayed when DriveSpace restarts your computer during the compression process, remove or disable the line in the Autoexec.bat file that contains Ps1pfile.exe. To do so, follow these steps.

  NOTE: The Ps1pfile.exe file may be necessary to use some of the Advanced Power Management (APM) features of Windows 95 and your IBM computer. If you are unable to use APM features reliably after removing the line that contains Ps1pfile.exe, insert the line again. If the message is displayed again after you insert the line, perform the steps listed above to work around the problem.

  1. Start a Windows 95 Safe-mode command prompt and then use any text

        editor (such Edit.com) to open the Autoexec.bat file.
  

  2. Remove or disable the line that contains Ps1pfile.exe. You should

        also remove or disable any lines that contain the LOCK or UNLOCK
        command that precede or follow the line that contains Ps1pfile.exe.
        For example, you may need to remove or disable lines similar to:
  

           echo y | lock c:\ nul
           c:\ps1tools\ps1pfile.exe
           unlock c: nul
  
        NOTE: To disable the first line above, you should modify the line
        so that it appears as follows (note that the second REM command is
        required):
  
           rem echo y | rem lock c:\ nul
  
     3. Save and then close the Autoexec.bat file.
  
     4. Restart your computer. When you restart your computer, DriveSpace
        should automatically continue the operation that it was performing
        when the message appeared.
  
  

STATUS

Microsoft is researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

When you install Windows 95 on a computer on which Ps1pfile.exe is running from the Autoexec.bat file, the Windows 95 Setup program automatically configures your computer so that Ps1pfile.exe is able to write directly to the hard disk. Configuring your computer in this manner prevents the message from appearing when you start your computer.

However, the Windows 95 Setup program is able to configure your computer so that Ps1pfile.exe is able to write directly to only the hard disks that currently exist. If a new drive is added, Ps1pfile.exe is unable to write directly to the new drive until you reconfigure your computer.

When you use DriveSpace to compress a drive, an additional logical drive is created. Because the new drive did not exist when you installed Windows 95, your computer is not configured so that Ps1pfile.exe can write directly to the drive. Therefore, if Ps1pfile.exe attempts to write directly to the drive when you start your computer, Windows 95 prevents it from doing so and displays the message.

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