GMOD wont show on the steam list when i install it i dont think it makes the .exe. any help would be great!

Where did you download it from?
If you downloaded it seperately from Steam, then search Gmod in the search engine built into windows explorer. I believe it may either be in the Steam folder or a seperate folder named Gmod.

You have to restart STEAM.

I've already tried restarting steam many times.
it is in the steam apps folder and also in its own folder in program files.
il try the search now

EDIT:
i just did the search and it found everything cept the exe to run it only the installer

Restarted the computer?

yes, ive done every thing i could think of: restart steam, restart computer, try installing gmod again, redownloading gmod, reinstalling steam, redownloading steam everything!

have you looked on the official gmod forums (if they have some....)

Make sure you have the latest version of GMod 9.0.4. For a while I was running 9.0.4a and was wondering why I couldn't connect to any servers. Try version C and see if it works: http://garrysmod.de/download-file-106.html

EDIT: You do have Half-Life 2, Half-Life 2: Deathmatch and Counter-Strike: Source right?

iv got all of them besides hl2, so i cant play it?

Err, you have to have HL2, I'm almost positive.

i dont see the link?

it looks illegal dude.

Lol, don't worry about it. It's not illegal, anyway, but yeah, just get HL2, then you should be fine.