COMP WILL NOT START UP

Hello,

I'm having problems getting my Dell Insperon 1720 to start. I'm running vista. This morning i turned on the power and it came to the user loading screen. I put in my password, hit enter, and while loading the computer froze. So i held down the power button to shut the computer off and start it up again. When the computer turned on the second time it would not start up. It comes to a loading screen (black background, DELL in big words, a loading bar at the bottom, runs on every start up), but after this screen instead of going to the user log in the computer loads an error report. The report gives me the option of starting windows normally or fix windows. I have tried both, neither will allow my compouter to start up both just lead back to the origional error report screen. So ii restarted again and this time when booting up i pressed f2 and told the computer to start up in safe mode. this also brought me to the error report screen. Next i pressed f12 on start up and ran a Pre-Boot System Assessment (PSA) Diagnostics test. This flaged me an error 2000-0333. IF anyone has any ideas as to what will fix this nd get my computer to start up plz plz plz let me know as soon as possible, i'm in university and i really really need my laptop to be working :(