Please help! Black screen after load screen.

hey everyone i was wondering if someone could help me? when the windows loading screen comes on it continues to load.. and when its finished it goes all black.. but when i type my password in i can hear the log on sounds.. and its not the VGA cable cos i tried lots of them. and its not the monitor cos i tried it on my TV (which has a VGA cable port) please someone help.:eek::
what is the make, model and model number of pc

laptop or desktop

I need this info to find your display adaptor as it may be corrupted, since you say the monitor works.