I have about 25 Windows 2008 R2 servers that are patched up to Jan 2016. 2 of them are not allowing me to connect through RDP from any client. I have tested three Windows 7 and one Windows 10 client that are also patched, and the result is the same for all of them - they can connect to all of the servers except for the same 2. The error from the 2 servers is "The remote computer requires Network Level Authentication, which your computer does not support." Of course, my clients do support NLA because they can connect to other NLA servers (which I have verified), plus the clients have RDC Client 6.3.9600 and explicitly state that Network Level Authentication is supported.
Even more details - I discovered this on the first problem server last night. I RDP'd in with no problem to check an SCCM issue. I didn't apply any updates. I rebooted as part of the sccm troubleshooting, and after the reboot, I got the first NLA error.
Any ideas what else I might check on the 2 servers?
Thanks.