Recovering after having a virus?

My computer got a virus a couple months back and it slowly got worse and worse until the computer couldnt do anything and would always tell me it needed a boot disk. After my friend used his boot disk to bring the computer back a little bit it still has a few problems.

whenever I turn it on it goes on and off really loud a few times before starting. Once it does get past the Dell screen it tells me it had a diskette drive 0 seek failure, once I bypass this windows kinda works. I'm not sure if the hard drive in there is working though. I switched out the hard drive to try and see if that would work and got a blue screen after I bypassed the same diskette fail message. So what can I do to fix all of this?