I recently backed up my half life 2 from steam and I have tried installing it via steam on another pc in the house but it wants the product key. I purchased the game from steam and not retail so I don't have a product key. Does anyone know if there is a folder where keys are stored or do I have some access to this info for all of my downloaded games via my steam account.
Did you log in with your account? If so, then you should have it listed in your library and available for download. If not, I suggest you send an email to the support people...
What I usually do (well, whenever the need arises) is to make a copy of the SteamApps folder. The on the new pc I install the STEAM client, log in and let it do it's mojo, then exit and copy the aforementioned SteamApps folder to its new home. Has always worked like a charm for me.
I'll give that a whirl but I didn't want there to be access to all my games on this pc. Its just so my daughter can fiddle with garry's mod when I'm not using steam and stop asking to go on my pc.
Well to use the mod she will have to login the account, hence giving access anyway. Of course, you could always just uninstall the other games afterwards and remove Steam from the Start Menu/Desktop and just leave a shortcut to Garry's Mod.