Black Screen

My girlfriend was switching on her Pc thismorning and the screen goes black after the very first windows screen, the one where you can choose system reocovery, Bios settings etc. after that screen pc goes black, and usually you need to hold down the power button to switch of pc But now i can turn it of just by pressing the button once. i can entrer Boot Menu and Bios but not system recovery. i'm really stumped ive done lots of searching but none was of help..

Thanx agen
Leslie:confused

 

things ive tried:

A) Checked Ram, Pc Beeps Without it and tried 1 stick in each slot by itself ( both pieces).
B) Disconected CD Rom as i heard this an cause Problems.
C) Took out Wireless Card.
D) Tried a Diffrent Monitor + Cable.
E) Tried a Diffrent Power Supply.

None of those worked..
I tried a Windows XP disc to see if it would load the Windows XP Disc which it did, So i'm LEt to belief a Virus Perhaps has completely Puckered the Vista Installation on her PC... Any Other Suggestions.. ? maybe a way to get it back up and working since i cant restore it with current problem..

 

try taking out the RTC battery and allow the CMOS to clear to default settings.
If it boots from the CD can't you try a repair install?

 

reseting cmos doesnt work, the recovery partion on drive doesnt work either, ive gone ahead and installed windows XP on it, and i can still see the recovery partition and acess it yet when i restart pc and press F11 to recover it doesnt do anything... apart from that its running ok on XP so far. i'll wait for dad to send me my Windows 7 Disc and i'll upgrade it