Ok, seriously. The support forum is here so people can get help from more knowledgable people like you and me, even though it may have been asked many times. If you think it's stupid, just don't post.

dont be so serious i was making a funny.

Now for my advice: I had this happen to me once and what I had to do is back up all my
important(or large) steam games and completely delete all traces of steam from its archive. Then reinstall steam and re download all your games and then try to install

Now this is a last resort but it usually works for me.

**Note this is coming from the man that does a complete rebuild of his computer once a year

Not just any man mind you, a fleshyman!

Dun dun dun...

rofl