I'm logged into a Windows Server 2008 R2 box as a domain admin. I'm trying to explicitly make myself local admin. From netplwiz, I choose add user, administrator, and click OK. Netplwiz becomes unresponsive and has to be killed. I try again: choose standard user, click Finish -- same result.
EDIT: Here's what was in Event Viewer:
The program NetplWiz.exe version 6.1.7600.16385 stopped interacting with Windows and was closed. To see if more information about the problem is available, check the problem history in the Action Center control panel.
I've never seen this before. Any ideas?