Arma2 CD Key

So I still have my legit cd-key... but I lost the handbook with the cd-key printed on it. I am planning on doing a system reinstall soon as I bought myself a SSD :3

The question is though: Is it enough to backup the Arma2 folders and the registry entries so that I can 'reinstall' it?

you can find your existing hex key in the registry or by using one of the hex key changers found here as they will display your current key. i guess you can then reinstall it using any old key then edit the registry again to match your legitimate key enabling you back online again