L4D1+2,HL2,Portal1 uninstalled today?

They are going to announce sequels on E3 :O

Actually, I don't have any idea.

HALF-LIFE 3 IS COMING

The installed games were a lie.

if only i actually own hl2, cause then i would be able to provide feedback. I'd say scan ur computer for viruses.

Now I have found out that it happened to Audiosurf and Beat Hazard too. Maybe some others but I do not know ... :/
P.S.: Scanning for virus right now

• CoD BO 1 but not MW3 :/

happened to me too, i waited and they the title magically turned white, strange thing.
only whit valve titles that you listed

Do you have them installed on different hard drives? Happened to me one time that steam would not pick up my other steamapps folder until i restarted.

uninstall steam and reinstall it
or go to your steam library or something press steam in the top left coroner then settings in the settings window go to account then under steam beta update change it to a different version
if none of that works delete system32

I restarted Steam and they are all magically back :D I think there was some problem with Steam update. Also no virus found. And all of them are at the same HDD on c:/

This happened to me as well, but instead, Star Wars: Knights of the Old Repulblic uninstalled itself.

There's a chance I might have accidentally done it at some point though.

HL3 is coming

What happened? You just don't know what you are doing (a.k.a. you don't remember what you uninstall) :P

It happened to me several times these days too, always with HL2. Going in C:Program FilesSteam and deleting ClientRegistry.blob, then shut down Steam and relaunch it to generate the file again.

Actually your games haven't been uninstalled, only Steam believes so. This should solve your problem.