Registrations of the 10.1 versions of Xilinx tools are not automatically enabled.
To request version 10, please review the Xilinx FAQ at http://www.xilinx.com/tools/faq.htm
NOTE: To receive the entitlements, you must be in warranty with the current version of the tool you are requesting.
If you want to purchase a Xilinx tool, please contact your local distributor. For a list of Xilinx distributors go to:
Once the version 10 entitlements are added to your account in the Product Licensing Center, sign in and navigate to the Legacy Licensing tab. Under the Legacy Licensing tab, select the tools you wish to register, select Register and a registration ID will appear.