it says my...?

[Ultimatevegie]

its says my cd key is in use so how do i fix it ? its when im joining a server and not lan server

 

[SierraSonic]

Buy Half-Life, not download it.

 

[Sonic the Vampire]

Or pick up another copy if your current copy is legitimate. There are plenty of CD key stealers and random generator users out there, so you might want to try again in a few days, or go pick up another cheap copy.