The serial number used by Enhanced Windows Backup is derived from a number of system parameters such as network card address, hard disk serial number, security ID etc.

If any of these things changes, then the serial number of EWB can change. If the serial number changes, then the currently installed activation code will not match with the serial number and EWB will throw up an error saying that you need to register.

If you are a trial user, then simply re-register with the new serial number. If you are a product owner, please contact support and we will clear your product token so that you can re-register with your original product token.

it is a known issue that the serial number scheme is over sensitive and we may address this issue in a future release.