two prob

[qwertz]

first everything on the desktop dissappeared then it got worse and i can not enter windows. when i login i have to choose shutdown reboot standbye and something else at the same time what makes the login senseless cause when i loging the pc jump back to the login screen or shutdown.

[qwertz]

windows xp pro
800mhz
amd-duron
in safe mode and last good known coniguration the screen also appears.i can not login without choose any of shutdown reboot standby or hibernate with the login together.when i login the next message is in the login screen is preparing to logoff LOL desperate can i remove the login in bios?