The computer of death

Our computer, which has struggled ever since getting hit with a virus a month or so ago, is on its last leg.  At least the hard drive, or the good folks at HP say.  I'm not entirely convinced, but being a novice tech fellow, I have no choice.  Like a person with no knowledge of cars at a garage.  An error 303 came up, and the HP folks said that was it, dead hard drive.  The computer wouldn't reboot and simply sat idling.  So we ordered a new hard drive.  Then at around 3:00 AM last night, bang!  It came on.  It keeps freezing, but so far reboots have worked.  Still, the HP folks (the ones who sold me the hard drive) insist there's nothing else we can do.  They said there is no other repair options, and continuing to use it could lead to worse results.  Don't know.  But right now, as if blogging wasn't scarce enough, I have one more thing to keep me from using this thing too much.  Sad part is, I don't know we'll be able to get all the programs over to a new hard drive.  Pray to whatever saint is the patron saint of technology.  Tune in to see what happens.  Any suggestions, and I'm all ears.