I transferred my main OS over to a Solid State Drive....

Now when I try and reinstall Crysis and when I enter my Serial number, it says "Serial number has expired, please call technical support"

Am I screwed here? I have NOT given my key out, and it's probably been installed 2-3 different times from me switching main hard drives, by either a new drive or a change of motherboard.

Who do I contact?

Sorry for the double post of this topic guys, IT WAS NOT INTENTION!

Your CD-key can be used to authorise 5 different computers and then I think you need to contact EA support to get them to reset the limit (you will likely have to supply them with some proof of purchase).

Alternatively, if you look in your Crysis 2 install directory (It will probably be in either the Electronic Arts or Steam/SteamApps/Common folder in Program Files) and look inside the Bin32 folder there will be an 'Activation' application that you can use to deauthorise an install and get an activation back for your CD-key, but I don't think that will work if it has decided you're now on a 'new' PC.

Right click the crysis 2 tab installed on your previous hard drive, and 'deauthorize this machine'.

Right click the crysis 2 tab installed on your previous hard drive, and 'deauthorize this machine'.
How exactly do I do this?

Well, your gonna have to load back up the game onto the old hard drive and once installed right click the crysis 2 tab on your start menu and select to deauthorize the machine, mind you i ain't never tried it but i believe that's what that function is for, basically to stop you lending it to your mates.