Hey there....
I'll tell it like it is....
You need to install a new hard drive in all likelihood as your current one is on the fritz.
To help for the moment, boot to safe mode then run this command from a prompt:
chkdsk /r
You're not going to lose any data so don't worry about that. But you should install a new hard drive and copy what you need off the original asap, after running that command.