take your hard drive out and put it in your new pc, as a slave, your files should be ok.
sounds like your PC is missing a file it needs to use when booting up, and maybe its been deleted.
but all your stuff will be on there, just make sure you do a virus scan.
you can also buy an external hard drive case and put that hard drive in there and use it as an external drive.
but once you got your valuablle files , fdisk it, then format it.