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 1 GiB.

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

I'd like to have those 2 GiB 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 2 GiB.

I also tried to limit the RAM to 999 MiB 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 1 GiB (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 2 GiB of RAM available under Windows 98.

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

  • 3
    The reference for this is this thread on the MSFN forums. Commented Mar 16, 2017 at 7:54
  • What did you set MaxFileCache to?
    – Algimantas
    Commented Mar 16, 2017 at 8:17
  • @Algimantas MaxFileCache is set to 524288. Commented Mar 16, 2017 at 19:24
  • 4
    IIRC, 999 is already too much. 960 is highest you should be setting there. If that's still too much, try 768.
    – Algimantas
    Commented Mar 17, 2017 at 7:36
  • 3
    @user2109 Mb/Gb is megabits/gigabits (1/8 of MB/GB). MB/GB is megabytes/gigabytes Commented Apr 3, 2018 at 14:35

6 Answers 6


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

  • Install Windows 98 with 1 GiB 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 2 GiB of RAM;
  • Start the system;
  • Windows 98 should now only have 1 GiB of RAM although 2 GiB 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 too much RAM for its cache.

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

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

  • 3
    Is it possible to use the remaining 1GB as RAM disc? That would make it useful. Commented Oct 17, 2019 at 9:25
  • msramdisk was always fun. Your suggestion is sensible though even if said ramdrive was just for /temp etc
    – AndyF
    Commented Jan 8, 2020 at 18:40

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.

  • 12
    For reference, 64MB was common for Windows 98 mid level PCs, 128MB to 512MB were enthusiast's configurations... Commented Oct 11, 2017 at 10:32
  • 3
    I am not impressed that a vendor built such machines. What impresses me is that the vendor was influent enough to make Microsoft take their requirements into consideration.
    – dim
    Commented Oct 23, 2019 at 10:45
  • I recall my 98 box had 32mb as default and I upgraded first to 64 then later to 128 . The difference in operation between 32 and 64 was very noticeable, the same way you can tell 95 was much happier with 32 over 16 but if memory serves (no pun intended) less so going from 64 to 128 . It was well past it's sensible life by then though as this was around 2000 which I jumped to . Virtual memory in 98 is worth playing with though unless you have 512 or more maybe.
    – AndyF
    Commented Jan 8, 2020 at 18:37
  • 3
    And BTW, even 32-bit linux systems in the early to mid 2000s needed serious know-what-you-are-doing if you actually wanted more than a gigabyte available to applications - there were "bigmem" kernels that could cause serious performance issues on the wrong hardware (see my next comment about cache...), there was the option of screwing with PAGE_OFFSET, and a lot of ways to get it all wrong.... Commented Feb 26, 2020 at 16:59
  • 3
    Oh, and ... a machine of that vintage supporting 2GB didn't always mean L2/L3 caches were functional across all 2GB. That easily left you with an accidental NUMA box and interesting performance surprises.... Commented Feb 26, 2020 at 17:01

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
    Commented Aug 2, 2018 at 18:24

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.

Update 2019-10-23: The above website is now down, and it seems the developer unfortunately passed away. Following this, somebody made the patch available here:


And it can now be downloaded for free.

  • 4
    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
    Commented Jul 19, 2019 at 18:08
  • 3
    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
    Commented Jul 19, 2019 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
    Commented Jul 19, 2019 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
    Commented Jul 20, 2019 at 13:57
  • 1
    Neither URL now works, the no-ip one doesn't resolve, and x10host shows account suspended.
    – Soruk
    Commented Sep 19, 2019 at 13:37

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, on the Internet Archive or Phil's computer lab.


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


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