ok ..you see, proces of ilimination is good. if you can get into PS, go and dissable the Adobe bridge.
the thing is, Adobe Bridge tries to alocate all pics into a databse, and access them realtime. This, is rather annoying sometimes .. and Nortons doesnt help either, thinking the program is some sort of threat.
Also, go into your windows firewall, and give permissions to ALM and Adobe bridge .. (under the add program).
next, try and creat a new doc.. 1024x768, and then <prntScrn> .. and then pressing <ctrl>+v to paste it into a new layer. If this works, then the rasteration and pixle graphs are fine, and a program error is eminent.
let me know.