Cannot add games to Gmod

I bought games from steam, and I cannot add them to my gmod
here are some pics:

Why do you have that open in Paint?

… so i could save it?

From that first screenshot, only Hl2:Lost Coast, TF2 and CS:S can be mounted to Gmod.

L4D2 runs on an incompatible engine version

Day of Defeat and Counter-Strike 1.6 are both GoldSrc engine games, also incompatible

HL2 is mounted by default because Gmod can’t run without it.

Next time, don’t save pictures in JPEG. Ever.
Use PNG.

Yes.
Clean your GMod.
If that doesn’t work.
Delete the GCF, and the local content, and start from scratch.
Still not working?
It’s something to do with GMod concerning updates. Infact, while I’m on the latter. Are there any new bugs (if updated)

No like I said, the only 3 games visible on his games list that are mountable by Gmod are Lost Coast, TF2 and CS:S, all of which are already mounted.