OOPS! Went back to it again this morning and realized I made a dumb goof during the install process. I went per the instructions, making a Windows directory and then a system.ini file inside it, but after initiating the Win98SE CD setup, I didn't notice that when it prompted for the Windows directory name, it suggested "Windows.000". I'm used to it always suggesting "Windows" and at first glance it looked normal and I accepted. The result was the installation process never even looked at my [386Enh] and [vcache] entries, it was busy building the system over in directory "Windows.000". And to imagine, the old problem was still there -- duh! (Note: Once in EDIT, to save the file and exit use ALT-F to open the "File" menu. Then type in the highlighted letter to make your menu selection.) This time, I stored the initialized copy of the System.ini file on my Win98SE startup diskette for the sake of convenience and after creating the windows directory, I just copied it over. Following the OP's instructions, I kept booting to the startup floppy and observed that on the first boot after startup, the [386Enh] entry was unchanged, but the [vcache] entry was deleted and I had to re-enter it. However, I found that on the second and all ensuing boots, neither entry had been modified and so no further editing was needed. Happy to report, Win98SE came up nicely with 2GB installed. I checked with Device Manager and was informed the system had 1022KB which must be how "MaxPhysPage=40000" works out. (I should mention I used a different spec for "MaxCacheSize", I specified 65536. Reason is the machine is for gaming and I read elsewhere a much smaller vcache is best for games, both since the video card typically needs a lot of virtual address space for its RAM window, and also because games usually want lots of direct RAM access. That particular size had been suggested.) In any case, the OP's procedure worked and I now have a functioning 98SE/XP dual boot with 2GB DRAM. Perhaps my experience will be helpful to somebody else. -- Thanks very much OP ! You're not alone if those "RAM tweaks" for Windows 9x above 512MB given here and elsewhere didn't work for you. They have never worked for me either. I purchased RLoew's RAM Limitation Patch, and have never looked back. What matters is you got it working, congrats. I was banging my head against this for over a week and it just seemed logical that with all the configuration tweaks the early Win systems supported, this should be workable. Apparently, the trick is to force all the automated setup decisions to stay within the tweak bounds from the very beginning, rather than trying to back-fill with msconfig later. When I said nothing had changed between boots, what I'm saying is that my initial edits remained intact. In any case, it doesn't matter, the system is now running exactly as I wanted, Win98SE and 2GB !