Buy new pc or try to salvage the HP I still have?

I own an HP 2005/2006 Media Center a1632x pc. Hard drive is dead for sure. I went to best buy to get a replacement HD(western Digital). Then I decide to call HP HQ cuz I dont have the orginal discs that came with the pc when I bought it. They tell me that I can try to install a working MIcrosoft XP OS copy when i format/reinstall windows to the hard drive but the likelihood of this actually happening successfuly is slim-maybe 5%. They claim that the drivers for this model are outdated or something and that they normally dont carry drivers for a pc 5 years and older. They also tell me that I am probably better off buying a new pc tower for $300 from them. Anyone out there familiar with this stuff please help me!