I hate to correct people, but as an IT person deploying XP, I have to chime in. What Gallion said is incorrect. XP is completely based off the Windows 2000 kernel, and will recognize and support 4 GB of RAM. Windows 95/98/ME have been hamstrung without tweaks at anything above 512 MB, but XP has NOTHING to do with those operating systems. XP will support 4 GB just fine. How do I know? My development machine at work is running XP Pro with 1 GB of RAM, with no hacks, no regkey tweaks, just the stock installation. My company also is beta-testing the next version of Windows servers, currently called .Net server. We have an 8 processor machine that has 3+ GB of RAM, again, the OS (it's essentially XP server) detected it all just fine. Please tell me you really meant to say ME doesn't like anything about 512 MB, because that would be accurate. If you look at the version strings of the files in XP's system directory, you'll notice a pattern: 5.1. That's because it is based off of NT 5 (Windows 2000). Not 95/98/ME. Not meant as a flame, but I hate seeing misinformation.