
Was this server promoted to a DC AFTER IIS was installed?
When IIS is installed, it sets up IUSR and IWAM accounts - in the local SAM database if a member server, or in AD if a domain controller.
If a member server with IIS installed is promoted to a DC, then the local SAM accounts are now inaccessable - so certain things in IIS stop working. A clasic example is the logoff screen in OWA.
One fix is to uninstall/reinstall IIS. Although I’m not sure if you can do this after Exchange is installed.
There are KB articles on how to fix this manually - but lots of misinformation (even from Microsoft… It’s NOT a permissions problem!!) also.
If this is your problem, and you can’t reinstall IIS, check out (just as a starting point):
KB 269367 and KB 255770
Regards
Colin










