The most likely problem is that the Serial Number: (e.g., 55VX4-55235-Q9EST-ERN89-4N6US ) was copied down incorrectly. Make sure the 2 is a 2 and not a Z, that the Q is not an O, the 5 is not an S, or the S is not a 5, etc. If you want to try a new Serial Number Type RENEW into the KEY box and click [Activate Product]. You can obtain your KEY online here. 1. Type in your DiskID and click [Submit] 2. Fill out the form and click [Get Key] 3. Copy and Paste, or type the key into your software activation screen and click [Activate Product]