game unavailable?

[DocClock aka MadClocker]

I don't understand this one...I spent almost two days d'ling and updating HL2 and after I played it a while Steam reported the game is unavailable. This is in win7 64 bit, but I have the game launch option set to 32 bit.
Ok, I was towards the end of HL2 anyhow, so I played HL2 ep1 for a while and quit to do a few things and Then I went to play again, and the game was unavailable.
I though I'll just restart the computer and the game was playable again.
Is this a bug, or are the steam games setup with some kind of torrent system?

[Leviathan41]

1) Close Steam
2) Delete the clientregistry.blob file (it's in your main Steam folder -- C:\Program Files\Valve\Steam\ by default)
3) Restart Steam and try it again
4) If that doesn't work do this:
# From the My Games tab, right-click on the game and select Properties from the menu.
# Select the Local files tab and click the Verify integrity of game cache... button.
5) Try it again

I've had it happen before in Steam and deleting or renaming the clientregistry.blob file fixed it. It seems to be very rare, I've only seen it happen twice in my 5 years of Steam usage, you just got unlucky.

[Shelnutt2]

I second the delete the clientregistry.blob file. When steam gives you trouble, and a simple log in/log out, or restart doesn't fix it. I delete the file and 75% of the time it's fixed.

[Badbonji]

If it crashes, sometimes the executable still runs and u need to stop it in task manager (hl2.exe). Did restarting actually fix it?