Yes, what Rattler said
The serial its also stored at the bottom of the general.opt file in the settings subfolder of the game installation (open the file with notepad).
Denny
The serial is also sent to you by email when you buy the game (if you bought if by download) or should be printed on the manual if you bought it by box.
Maybe you still have it on you mail program
In any case, be sure to store a copy of the serial somewhere safe.
I have it in my backup disc stored on a txt file with the game installation file i downloaded form AGEOD.
This two things are all you need to install the game in other of your computers, present or future ones.
There is no DRM, limited installations or complicated transfer protocols w9ith AGEOD. Just a simple install file+serial number
Cheers!