u/Fun-Rip2151

Hello! My PC is over 10 years old. I mostly use it for browsing the web, playing emulators and some steam games. My best friend built it for me using the website build a pc. How can I tell what he used if I open it up and what will fit in a new smaller tower? I don't know anything about computers and how to sodder or do things like that.

In order to better help you all with my new build, how can I tell what my power is, my ssdd cards, etc?

I'm sorry for being dumb. I can edit and update my post with the more i learn from you all.