Hey Irachtus, welcome to DoF, and sorry to hear it`s off to a sucky start.
If it doesn`t do anything on checking the product key, disable your windows firewall and anti-virus and try again (or add DofUpdater.exe as exception to both).
If it crashes after that or stops responding, or if above didn`t work - follow these steps: http://www.reverieworld.com/forums/s...14&postcount=2
If it just tells you Invalid CD key, or expired CD key - e-mail your CD key to email@example.com
and they can fix it for you by issuing a new one.