TF2, CS props/ragdolls are gone

I recently installed…well no, correction, my cousin installed some things on Garry’s Mod, and those things are, I’m certain, are fortification props and maybe a few other things (conveniently, he doesn’t recall what else he threw into my game). So eventually I get bored and kick him off and realize that the TF2 and CS props and ragdolls will no longer spawn. The icons are there, but the things themselves won’t spawn.

I’m almost certain it had something to do with something being installed, so my question is: how, exactly, would I be able to restore the TF2/CS props, if I can? Would a complete re-installation of Gmod be necessary?

Do you actually own TF2/CS? Becuase if you downloaded them on a free weekend then it ends, you still have the spawnlists but they won’t work. Try clearing your addons folder. (back it up first)

Yes.

I just found out that now the Portal props won’t work.

I’ll try doing that, but I DO own all three games. I bought the Orange Box, so…

It’s not working.

Ugh. So is there any way for me to just re-download the specific CS and TF2 files back into Gmod?