Typically the ActivInspire Serial Number is found on the board itself on the bottom right hand corner, it says Activation Key.  If for some reason the sticker has been removed you can still retrieve a serial number from Promethean Planet following these easy steps.

1. Go to www.prometheanplanet.com and create an account.
2. Click Support on the top navigation bar.
3. Click the link on the top right of the page to Download ActivInspire.
4. Select US English
5. Scroll to the bottom of the page to the section about Serial Format and select Hardware Serial Number.
6. Located on the left side of the board typically by the volume and cable inputs is the board serial number and product code.  Enter those values and click Validate.
7. That will return an activation code which you can use as the Serial Number when registering ActivInspire.