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PC Hacks
By Jim Aspinwall
October 2004
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Tame the Windows 95 and 98 Cache
Stop Windows 95 from consuming all your RAM by fixing the VCACHE bug
[Discuss (0) | Link to this hack]

Microsoft does admit to a specific limitation of Windows 9x memory use in their Knowledge Base article 253912 (http://support.microsoft.com/default.aspx?kbid=253912). The article points to very real problems you may encounter if your Windows 95 or 98 system contains more than 512 MB of RAM. The article addresses a known problem with the VCACHE disk and disk caching driver, and the possibility that it may consume all available memory, up to 800 MB, leaving no memory for programs and data. There is a simple workaround for this—control the amount of memory VCACHE can use by changing its parameters following these steps:

  1. Using Notepad, Edit, or another suitable text-only editor of your choice, open the C:\WINDOWS\SYSTEM.INI file.

  2. Find the [VCache] section, which may have no contents under it. If a [VCache] section does not exist, create a new line entry for it just as it's written here, usually below the [386Enh] section.

  3. Create or change the MinFileCache= and the MaxFileCache= lines with the desired new values, expressed in kilobytes.

  4. If you want to create a 32 MB cache that does not grow larger than 40 MB, the lines should read:

  5. Save then close the modified SYSTEM.INI file and restart your PC.


Although VCACHE could consume more memory than it should, and supposedly will consume more than 512 MB, and Microsoft recommends setting the cache limit to 512000, they also claim they have not tested VCACHE settings larger than 40 MB, citing that unpredictable results or data loss may occur with values larger than 40 MB.

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