Initially check the leads inside. That sort of error is usually when it can't find the hard drive. But if it starts to load windows it could also be that theres something wrong with the windows installation. And you could try safe mode if it gets that far - press F8 at startup.
Probably a corrupt OS installation - could be a hardware problem, could be software.
Unless you have a CD to reload an OS you're not going to get far.
You could take the drive out and mount it in another computer - then you can try and get any data off that needs saving, and check out the drive with a diagnostic program (depends on the drive manufacturer).