I do hope that "tech" isn't a close friend or relative, because he appears to have been talking out of his backside. The question is: what do you want to do? If you are looking to upgrade your computer, you will probably need to change motherboard, processor & fan. You may also need to change graphics card and certain other add-ons. It really depends on how big a jump you're making. If you're upgrading the lot, the only thing you'll really be able to resuse is the floppy drive & CDROM. Nothing else is going to be up to the job.
So tell us a bit more about your project we can perhaps try and give you slightly more balanced advice...