Steam Error: "The game is currently unavalible. Try again later"

[Wetwilly?´´?´°]

Okay so for the past couple of days I've been getting this message, "The game is currently unavalible. Try again later" when trying to launch  Counter Strike, Gary's Mod, Half Life 1, and Team Fortress. Portal one and Two work fine, and so does Half Life two. So far I've tried Verifying Integrity, Defraging, Re-installing said games, and re-installing steam. Nothing has worked so far. I've also tried going into my steam folder and launching the hl2.exe from there, but I get this message, "Setup file 'gameinfo.txt' doesn't exist in subdirectory 'hl2'. Check your -game parameter or VCONFIG setting." Except when I try launching hl1 from the folder, I just get "The game is currently unavalible. Try again later" again.  So yeah, I don't really know what to do from this point, but I really want to play Gmod. I'm open to suggestions.

[MrVolker]

I've been getting this problem lately too. Here are some things that (I think) worked to fix it:
1.Turn on another steam game for a few minutes than retry the one that was unavailable.
2. Log out and then log back in.
3. Restart Steam.
4. Restart your computer.