1)Windows Server 2012R2 evaluation windows license is expired.
2) run “slmgr.vbs /rearm” to extend license another 180 days.
3) Reboot the server, and the license is extended for another 180 days.
Windows Server 2012R2 Datacenter Evaluation License Expired
It is a good for us to have Windows Evaluation for building your own lab and playing around new technologies.
Make DBA Life Easy 