Deinstallation of Ditital Edition 2.0 for new PC installation

Hi.

I've installed Digital Edition 2.0 on my PC for a year now, everything works fine.

Now I want the make my PC new, installing Windows 7 again.

Can anybody explain me, how I can deinstall DE 2.0 before the remasterisation without loosing one license and without loosing the books I have bought?

Thanks a lot