PRB: Limited Virtual Memory Error When Starting Windows NT

The information in this article applies to:

• Microsoft Windows NT operating system version 3.1
• Microsoft Windows NT Advanced Server version 3.1
• Microsoft Windows NT Workstation versions 3.5, 3.51 and 4.0
• Microsoft Windows NT Server versions 3.5, 3.51 and 4.0

SYMPTOMS

Around the time of the logon prompt after starting Windows NT, you may see the following error message:

   Limited Virtual Memory
   Your system is running without a properly sized paging file.
   Please use the virtual memory option of the System applet in
   the Control Panel to create a paging file or to increase the
   initial size of your paging file.

CAUSE

Windows NT is not able to correctly gain access to (or open with proper permissions) the Pagefile.sys file. If the partition is NTFS, it may be because the permissions are not set up correctly. By default, Windows NT sets up the root directory to give everyone full rights. When this right is changed, you may see the error message because the System may not have proper access to Pagefile.sys. This can happen when Administrators try to limit access to the drive on which Windows NT is installed. The System must have access to read the directory. If the System does not have permission to read the directory, it will not be able to access the file even if the System has full access rights on the file itself.

RESOLUTION

The best solution is to add the user System with full access to the root directory. By default, File Manager will update all the files in whatever directory that is being modified to give them the same permissions, so it will give the System full access to the directory and the Pagefile.sys file.

Usually this is good because you would expect all the files in that directory to have the same permission. But if you try to set the directory to have fewer permissions than a file in that directory has, at some time in the future, you may accidentally overwrite those broader permissions with the lesser directory permissions. This can happen by simply viewing the permissions for the directory and clicking the OK button. As stated above, the default setting is to replace permissions on files in the directory, so this replaces the greater permissions; in this case, it gives the System Read access on the directory but Full access on the Pagefile.sys file itself.

Editing the Registry as a Workaround

To work around this, you can edit the registry. However, this can be dangerous.

WARNING: Using the Registry Editor incorrectly can cause serious, system- wide problems that may require you to reinstall Windows NT to correct them. Microsoft cannot guarantee that any problems resulting from the use of the Registry Editor can be solved. Use this tool at your own risk.

1. Locate or create a directory for the Pagefile.sys file. This could be the Winnt directory, which by default should have System Full access.

2. Make sure that this directory has System Full access and that all previous directories including the root have at least System Read access.

3. Start Regedt32. Select the HKEY_LOCAL_MACHINE on Local Machine subtree, and search for the following subkey:

   SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management

4. On the right side of the window, choose the PagingFiles :REG_MULTI_SZ: value.

5. Either double-click it, or from the Edit menu, choose Multi String.

6. Edit the string, and insert the full path for where you would like the Pagefile.sys file to reside. For example, change C:\Pagefile.sys 44 100 to C:\Winnt\Pagefile.sys 44 100. (Here 44 refers to the minimum pagefile size and 100 the maximum.)

7. Exit Regedt32.

8. Restart the computer, and check to make sure Pagefile.sys appears in the correct location. Then delete the Pagefile.sys file in the root directory as this file is no longer be used.

STATUS

This behavior is by design.