Steam Update = Have to Reinstall Half Life 2?!

[Aphexxx]

Ok,what's going on now?!?!
I just downloaded the newest steam update and it says that Half Life 2 is no longer installed??
wtf is going on?
do i need to reinstall the whole thing again?

 

[^Ben]

Close steam,

Delete clientregistery.blob

Then find platform.gcf and delete that and start up steam and see what happens.