Limited Access Issues

I have an inspiron 1545 and out of the blue while taking an exam monday the limited access came on. I spent and hour and a half troubleshooting with clear wire. the next night I spent an hour troubleshooting with dell. Finally saturday I took it to the geek squad and even they didnt know how to fix it. I read some of the forums and maybe somebody can help me with this issue, my next online class starts today