i am going to install my winxp OEM to a pentium 4, 128mb PC. i was just wondering... should i decide to upgrade from 128mb, would the OEM still work after the upgrade?

The OS doesn't care how much RAM you have. Go for it! Tomorrow the Stars!

The OEM should operate like the retail edition. The only differece that I know is that you don't get the box and manuals. Just the disk. I do not think that updating the ram later on will cause the computer to not work. Unless the ram is bad or is not put in correctly. But I would advise at least 512 MB of ram with XP. I know that my computer, Running XP Pro, uses up around 350-450 mbs of ram doing nothing. (according to the Alt-Ctrl-Del menu) Short Answer: Yes, it should still work. Hope this helps! George Please respond after you have solved your problem to notify who helped you and what solved the problem. Both sides benefit when you do.

Minimum Recommended is 128, but XP will run on 64. http://www.microsoft.com/windowsxp/pro/upgrading/sysreqs.mspx These answers are both correct, won't matter whether you upgrade the ram now/later sine you meet the required (even minimum), but you will definitely see an improved install time if you upgrade before. Just for though! Michael Live, Love & Google!

It sounds like you are more worried about the OEM XP not validating after the upgrade rather than the upgrade being compatible or beneficial. Each change you make to your computer is scored by windows and if the score gets high enough you will have to call in to get permission to activate windows. But, a simple memory upgrade won't cause any problems.