my PC showed me a message saying a had a corrupt file in system32. that stuff all concerns booting up doesnt it?

well my PC wouldnt start any more so tried a few methods then ended up fully formating it but still no luck!

so question is ... can i buy a new hard drive and put it in the old tower? or is system32 part of the motherboard and i'll need a whole new tower?

thanks in advance, really clueless about this side of IT!