Now i cant even join a game because POS Steam says my HL CD-KEY is in use, havent loaned it to anybodyWhat do i have to do?

No do not reload it......You may have registered another email address. It ties your CD key to your email address and will only allow 1 person to login with it. So if registered at your friends house it used his CD key. Tell me a little more ...how many email addresses have you registered..were you at home when you signed up for steam?I have had the same problem and got it fixed....I had like 6 email addresses I had used but there was only 1 that tied to my CD key so I had to get help to find out which one it was....so try this first!I have a contact at valve if you are still having problems....