Activate windows, and a empty Device Manager

[tmac2085]

I left my computer on downloading a couple of things like i always do. and when i turned on my monitor this morning i get a window saying I need to re-active windows due to hardware changes to my system. I haven't made any changes with my system. So i tried out my internet, and NOGO, its dead. So i decided to check the device manager, and come to find out there is nothing in there (just white, nothing listed)! Also under the General tab in the System Properties listed under "Computer:" just has my RAM, it doesn't show what processor or anything. Did i just get hacked? I've never seen this before. I'm not at my home right now, so i really cannot troubleshoot. When i get home later today i might just wipe out the HD and start over. What do you guys think? Thanks for any help!

my specs:
Win XP Pro SP2
Dell Dimension 4550 2.53 GHz
768MB RAM

 

[smah]

Start with KB311504 because it's the easiest to verify, but the root cause could also be KB893249 or KB914450