I've got a few servers which are meant to be activating against an internal KMS Host.

As part of my troubleshooting I've been running 'slmgr /ato'.  I keep getting 0x80070005 Access denied: the requested action requires elevated privileges.

I'm running this command from in an Administrator Command Prompt.

Other servers 2012r2, 2012, 2008r2 I can run the same command with no problems.

Hi

 Make sure on server avaible to KMS on port 1688/TCP;

from server (which need to be activate)" telnet xxx.xxx.xxx.xx(kms server ip&hostname) 1688"

If it is OK.Check this article to manually activate;

http://www.it.cornell.edu/services/software_licensing/howto/kms-server-manual.cfm

Or you could activate by using Volume Activation Management Tool (VAMT) 3.1

https://technet.microsoft.com/en-us/library/hh831612.aspx

Port is open, telnet to port 1688 works.

Access Denied when I try to Activate windows using VAMT 3.1 or 'slmgr /ato' from elevated command prompt on the server.

Hi

 User Account Control (UAC) prohibits activation processes from runing in a non-elevated cmd.

Run slmgr.vbs from an elevated command prompt,Rigt-click cmd.exe,and then clich Run as Administrator.

https://technet.microsoft.com/en-us/library/dn502528.aspx?f=255&mspperror=-2147217396

We've got a GPO that sets the UAC to it's lowest level and I've been opening "Command Prompt (Admin)" as well as searching for cmd right clicking and selecting "Run as Administrator" hence my initial question.

I hope you didn't configure them with a KMS Product Key, right?

Just to make sure. Clients that should activate against a KMS Server should not be configure with a Product Key at all. A KMS Product Key should only be used once, on the KMS Server itself.

If you accidently configured another Product Key on your clients you should reset it back to the default KMS Client Setup Key that is configured during Windows Setup. Use the following link for more information:

Appendix A: KMS Client Setup Keys
https://technet.microsoft.com/library/jj612867.aspx

Oh, and one other thing; Another thing you should check is the version (KMS level) you used to active the KMS Server. Always use the KMS Product Key for the highest Operating System edition. (e.g. Datacenter Edition instead of Standard Edi