So I downloaded Toribash onto a PC last night, and the program crashes when I click on Multiplayer. I even re-downloaded tb to see if that was the problem, but nothing different. Everything else works and it has all the files, as far as I can tell. And yes, I downloaded the right file (this is a PC, not Mac or anything else).

Have you tried this http://forum.toribash.com/showthread.php?t=214180

Yes, I downloaded the new C++ thing I needed to, but still not a thing..

Try cleaning your system and check for errors.
Have you tried playing multiplayer before with the same PC?

Well I didn't download it to the PC till last night... It's not mine, so I can't clean it...

Support can help you more than here.
Moved

Could you post the contents of your stderr.txt, located in your Toribash directory?