If your running a EUC lab environment it would be handy at times if you could reset the windows server RDS licensing period. Luckily this is possible.
It can be quite frustrating when you are testing out some things in a lab and the RDS grace period expires meaning you have to rebuild the session hosts (not too much of a problem with MDT but still a hinderance none the less).
Anyway all it takes is deleting a single registry key and the grace period is reset back to 120 days. Simply run regedit and navigate to the following location HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\RCM\GracePeriod.
Now delete the Reg_Binary entry within the GracePeriod folder by taking ownership of the GracePeriod folder and giving yourself full administrative rights over the folder.
Once that Reg_Binary is deleted simply reboot the vm and continue your labbing!
Author: Dale Scriven