Existing ArcGIS for Desktop users
ArcGIS 9.x and 10.0 users
You must uninstall all previous ArcGIS products and any third-party extensions or tools from your machine before proceeding with the ArcGIS for Desktop 10.1 installation. You must also uninstall your ArcGIS 9.x License Manager.
Concurrent Use users
You do not require a hardware key. However, you will need to obtain a new authorization file. You must install the ArcGIS License Manager, available with ArcGIS 10.1 for your ArcGIS for Desktop, ArcInfo Workstation, and ArcGIS Engine Runtime software. The ArcGIS 10 License Manager can support all Concurrent Use versions of ArcGIS 10, 9.x ArcGIS for Desktop and ArcInfo Workstation, as well as ArcGIS Engine Runtime 10.x.
Single Use users
You must obtain a valid authorization file for your ArcGIS 10.1 Single Use product.
ArcGIS 8.x users
You must uninstall all ArcGIS 8.x products from your machine before proceeding with the ArcGIS for Desktop 10.1 installation.
Uninstalling previous versions applies to all 8.x to 9.x users. See Uninstalling previous ArcGIS products for details.
Concurrent Use users
You will need to obtain a new authorization file. For more information, see Obtaining an authorization file. You will be required to define a valid license manager after installation.
Single Use users
You must obtain a valid authorization file for your ArcGIS 10.1 Single Use product.