Windows 7 ultimate activation key, windows 7 serial number problems

Activate Windows 7 or Windows 8.1

Activation helps verify that Windows has not been used on more PCs than the Microsoft Software License Terms allow.

To activate Windows 7 or Windows 8.1, you will need a product key for the version of Windows which is on your PC A product key is a 25 character code that looks like this:


Finding product key depends on how you obtained your copy of Windows 7 or Windows 8.1:

If you purchased Windows from an authorized dealer, the product key will be located on a label on the box that was delivered product ..
If you bought a new PC running Windows product key is pre-installed on the PC, included in the package was delivered to PC or Certificate of Authenticity (COA) attached to the PC.
If you buy a digital copy of Windows from a Microsoft Web site, the product key is in the confirmation email that you received after purchase.

See more details on Microsoft website.