sounds like a harddrive failure, are you able to load windows at all? or does it crash half way through the load bar?

if its a hard drive failure theres a few things you can do....

1. get really pissed off and throw you computer out the window
2. plug your harddrive into another computer and see if you can get any data off it
3. harddrives have alot of moving parts and sometimes they just get stuck, if you cant get anything to work, take the harddrive and bang on it a little, this will sometimes allow you to access it for a little while, but its going to happen again and you may not get it to work again
4. if its still covered under warranty, your supplier will replace it but you will loose all your data...
5. if your data is REALLY important you can spend some money and get it recovered by professionals, this isnt cheap though

i would need more information on the error and when the error occurs before i could confidently say that this is in fact a hard drive failure...

~Raelum