I decided to change my XP CD key to the one I just got from MSDN through my school. Since my install was OEM and my new key was retail, I booted to the retail cd, chose my install of XP, and hit R to 'repair' it to the retail version. (Google tells me this is how you switch an OEM install to a retail one)
It took quite a while, but eventually it asked for my new key and for my regional settings. Now I am at the XP welcome screen, and everything looks normal. Except Windows Genuine Authentication tells me "you must activate this copy of XP before you can log in. Do you wish to activate? [yes/no]"
If I click no, I can't advance past the welcome screen. If I click Yes, my wallpaper loads and I can move the mouse cursor around, but nothing ever comes up. I'm stuck with a blank desktop indefinitely. I'm never given any sort of activation screen or whatever is supposed to come up.
I'd call Microsoft for a phone activation, but something tells me they'd just give me a number and I'd have nowhere in which to type it! I even read that you can bring up the Microsoft Narrator with win+U and click a link to open IE. I can do that, but clicking the link does nothing.
more info: -I can log in to safe mode (without networking) just fine. If I try safe mode +network support, the welcome screen tells me I can't activate XP in safe mode and I have no choice but to restart. -No clicks or keypresses seem to have any effect on the blank desktop, except win+U. Not even ctrl+alt+delete does anything.