RDP (Remote Desktop) temporary per client licenses will only be created the first time a client logs in. In general they have a 90 days validity period, after which, if no real certificate is issued, the client access is going to be denied. If you have no problem with re-creation of theses temporary certificates for your client and only use these, it's quite simply to renew every certificate for RDP.

Simply open the command-line (cmd) and do:

• net stop "Remote Desktop Licensing"
• del /Q c:\windows\system32\lserver\*
• net start "Remote Desktop Licensing"

That should be it. All certificates are gone and a new database will be created as soon as the first user logs in. To empty your database on a regularly basis, just create a batch file and let it run every month.