How to Register/Update an ArcGIS 10.x Single Use License

Update Single Use License:

1. Submit an IT Help Desk ticket to request a Single Use license.
2. Once you receive your license number, go to the ArcGIS Desktop Student Trial page.
3. Create an ESRI Account or Sign in in using your ESRI Account.
4. On the Activate your ArcGIS for Desktop 10 Authorization Number page, enter the EVAXXXXXXXXX number and click Activate ArcGIS.
   1. If ArcGIS is already installed on your computer, do not select a version to download.
5. Right-click ArcGIS Administrator (Start > All Programs > ArcGIS > ArcGIS Administrator) and select Run as Administrator.
6. Choose Desktop > Advanced (ArcInfo) Single Use and click Authorize Now.
7. Select "I have installed my software and need to authorize it.", click next.
8. Select "Authorize with Esri now using the Internet.", click next.
9. Enter all of your personal information and the Authorization number.
10. Click Finish.

Also see this Activation Guide and this Authorization Guide if you have trouble.