Is my Garry's Mod trying to reinstall games?

Whenever I startup Gmod, everything is fine and then it gets stuck loading at the title screen. I tried waiting a while patiently but no avail. It would just sit there and say “Loading…”

Then it dawned on me yesterday that perhaps Garry’s Mod is trying to reinstall my currently unistalled VALVe games so that it can access those games’ content for use in game. Currently, I have Counter-Strike Source, Day of Defeat: Source, Portal 1, and all the Half Lifes uninstalled. Is Garry’s Mod trying to reinstall ALL these games, thus causing the extremely long loading screen?

EDIT:

Attempt to ask for help and learn.

Get rated dumb.

Why are you asking me this question? How did you get on my monitor?

Serious: Something like that’s happened to me before, try uninstalling Gmod first.

It’s not.