Vista - only start in safe mode

My hp computer will only start in safe mode. When I try to start in normal
mode the screen goes blank about 20 seconds after I type in my security
password and it stays like this until I hold the power button to turn it off.
The cursor moves, and ctrl+alt+del pulls up the task manager but it only
shows about 4 programs working, the windows taskbar, desk manager are two of
them. I have performed a system restore, and it didnt work. Neither did a
full system disk check.