I have assembled a retro-gaming PC out of an old Shuttle SN45G with a Windows 98/Windows XP dual boot.

The motherboard can handle 2GB of RAM, but apparently Windows 98 can only handle 1Gb.

Windows 98 boots fine when I have 1GB of RAM installed, but I get the error Not enough memory if I install 2GB of RAM.

I'd like to have those 2GB of RAM permanently installed as I also have Windows XP on this PC.

I tried setting the MaxFileCache parameter to 524288 in the [vcache] section of system.ini but it didn't work with 2Gb.

I also tried to limit the RAM to 999MB with msconfig advanced settings but I ended up with a very unstable system (I get a black screen or a BSOD every few minutes and I'm forced to reboot).

I thought of trying to limit the maximum memory of Windows 98 to 1GB (apparently it can be done with the /maxmem boot parameter, but I don't know how to do it), but I don't know if it would work, and I would like to have those 2GB of RAM available under Windows 98.

How can I have 2GB of RAM under Windows 98? Or, in last resort, how can I limit the maximum RAM of Windows 98?

  • 2
    The reference for this is this thread on the MSFN forums. – Stephen Kitt Mar 16 '17 at 7:54
  • What did you set MaxFileCache to? – Algimantas Mar 16 '17 at 8:17
  • @Algimantas MaxFileCache is set to 524288. – Informancien Mar 16 '17 at 19:24
  • Strange, this is the same value that I have. Is the section named [vcache] or [VCache] in your file? I am finding solutions with capitalized letters only and in your question section name is lowercase (though in theory this shouldn't matter). There's another option setting MaxPhysPage=30000 in the [386Enh] section of System.ini which limits used memory to 768MB. – Algimantas Mar 16 '17 at 19:33
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    IIRC, 999 is already too much. 960 is highest you should be setting there. If that's still too much, try 768. – Algimantas Mar 17 '17 at 7:36

I might have found a stable way to limit Windows 98 to use only 1Gb of RAM with HimemX:

  • Install Windows 98 with 1Gb of RAM or less;
  • Download himemxfrom https://sourceforge.net/projects/himemx/;
  • Extract himemx.zip and copy himemx.exe to C:\Windows\ under Windows 98;
  • Open the Run dialog box (Windows + R), type sysedit and press Enter;
  • Open the file C:\CONFIG.sys;
  • At the very beginning of the file, add device=C:\WINDOWS\HIMEMX.EXE /MAX=1048576;
  • Save the modification;
  • Shutdown your system;
  • Install the 2Gb of RAM;
  • Start the system;
  • Windows 98 should now only have 1Gb of RAM althought 2Gb are installed and it should still be stable.

You can also add MaxFileCache=524288 under [vcache] in system.ini to ensure that Windows 98 doesn't eat to much RAM for its cache.

Limiting RAM to 1Gb with HimemX seems like a stable fix, but I couldn't get the 2Gb of RAM to work under Windows 98. But it still enables use of 2Gb of RAM under another OS in a dual boot setup.

P.S: If there are no answer posted in the next few days that explains how to fully use the 2Gb of RAM under Windows 98, I'll mark this one as the answer.

  • 1
    Is it possible to use the remaining 1GB as RAM disc? That would make it useful. – the busybee yesterday

The Windows 98 memory manager only supports a maximum of 1GB. This amount of memory was considered beyond huge for the time, and by the time people commonly had that much or more memory, Microsoft expected people to be using either newer versions of Windows 9x, or Windows NT.

From Raymond Chen's blog The Old New Thing:

Windows 98 bumped the limit to 1GB because there existed a vendor (who shall remain nameless) who was insane enough to want to sell machines with 1GB of RAM and preinstall Windows 98 instead of the much more suitable Windows NT.

The linked blog post also goes into the technical reasons why.

If your workaround works, then stick with it. You'll only ever be able to use 1GB of RAM with Windows 98, but XP will be able to make use of the full 2GB.

  • 7
    For reference, 64MB was common for Windows 98 mid level PCs, 128MB to 512MB were enthusiast's configurations... – rackandboneman Oct 11 '17 at 10:32

I have never tried it, but there is apparently a third-party patch for the Windows 98 virtual memory manager kernel driver that enables it to support larger configurations, up to 4GB. See this newsgroup post for details.

  • 1
    @Wilson - I'm not convinced there is anything else to add to the answer. As I understand it, if you install the linked patch, Win98 supports 4GB of RAM.... That's all there is to it. – Jules Aug 2 '18 at 18:24

I managed to get my 2GB RAM dual Pentium III vintage rig project to use 1100MB RAM.
Built up the Windows 98SE software on VirtualBox first.
Then I just transferred the virtual disk to a physical one with 7-zip and sys command to make it bootable on the vintage.
Runs like new, AGP aperture is much more stable. Come to think of it, 1GB RAM on a virtual machine with 4GB RAM-Disk as a swap disk really works well too.
Perhaps someone could make a RAM-Disk for DOS for say 3GB RAM in XMS as a scratch disk.
Anyhow, there is no way Windows will use more RAM unless system files are replaced with better ones that are either in a different language or some dope decided to put a price tag on. Windows millennium can run with 2gb ram perhaps someone could port these parts to 98se

  • Welcome to Retrocomputing Stack Exchange. Thanks for the answer! You might want to check out the tour. – wizzwizz4 Dec 15 '18 at 16:57

Purposely registered here to let know. Sadly can't comment due to the 50 reputation limit

Traditionally, the solution provided by Aoresteen is the best. Unfortunately, rloew has passed away in September 2019. Rest in peace

The full version of his patch is now available for free, here

New contributor
tabdiukov is a new contributor to this site. Take care in asking for clarification, commenting, and answering. Check out our Code of Conduct.

Spend $24 and get R. Lowe's patch for Windows 95 to ME. I use it on a 4GB Windows 98SE computer - Rock Solid.


This is the absolute best solution.

  • 2
    I did not downvote, but I suspect whoever did thought your post sounded more like an ad than an answer. You might want to tone it down a bit. "This thing exists. It might solve your problem because {...} . It worked for me in a similar situation. Downside is it will cost you $20." – RichF Jul 19 at 18:08
  • 2
    Additionally, you should use the direct, permanent URL http://rloew1.no-ip.com/Programs/Patchm.htm instead. Additionally, please disclose any conflicts of interest you may have in suggesting this product. – wizzwizz4 Jul 19 at 18:34
  • 1
    Thanks. Did not want to sound like an ad. Just a user that needed a 4GB WIn98SE stable computer for my recording studio and this worked. – Aoresteen Jul 19 at 18:54
  • Aside: there's also a demo version available from the link wizzwizz4 posted, so the poster could try before they buy. – Tommy Jul 20 at 13:57
  • Neither URL now works, the no-ip one doesn't resolve, and x10host shows account suspended. – Soruk Sep 19 at 13:37

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