Why did Steam erase all my games?

Solution 1:

I know of only one way that this can happen in windows, and has nothing to do with Steam other than their not-so-great decision to install all content into Program Files.

If you are on Windows 7 or Windows Vista, and you have UAC set to ON, then change it later to OFF, this can happen.

UAC does thing evil thing where if a program tries to write to a "protected" area like Program Files, EVEN IF YOU ARE ADMINISTRATOR, when you get a UAC prompt and give permission, it actually writes any files that would normally go into that directory into a "virtualized" directory somewhere else.

If you turn off UAC, that will no longer happen, and as an awesome bonus, it will no longer know about the files that it virtualized.

So in your case, if you had UAC on, installed a ton of games, then later got sick of UAC and turned it off, this would happen as you described.

See the second paragraph in "Features" in the article on User Account Control.

If you have done this and turn on UAC again, your content will come back, but be a TOTAL mess because if you've downloaded more stuff with UAC off, then that will be invisible when you turn UAC on, and vice versa.

this drove me a little crazy once before I realized what was happening.

i'm curious to know if this is your issue.

Solution 2:

Te best solution I can come around is to simply NOT let Steam install itself into Program Files, instead I install it on something like C:\Steam directly, so windows can't come around and smack me with UAC whenever i log in or out.

The real issue here is that the Steam client is very buggy on its implementation of installed content. Sometimes it just deletes the content because another account was logged in or you logged in to some other account.

I had a related thing going on.

In my house i have 2 desktops and a laptop. My desktop has always had the steam client installed and it has the guest account enabled. A week ago my brother setup a steam account, installed the client on the second desktop and I gifted L4D2 to him. When I went to work he used the guest account on my desktop to log in to his account, logging out of mine.

As soon as i came back to log in, steam had erased Fallout 3, Skyrim and Mass Effect 1 & 2 without any reason other than logout. It has happened 3 times now, so I asume it is a bug in the Steam Client.