Here is another tip to help troubleshoot advanced client issues. Run wbemtest and attempt to connect to the system that is behaving badly:
1. Launch wbemtest, and connect to
\\yourbadsystem\root\cimv2 <file://\\yourbadsystem\root\cimv2>
2. If you receive error number 0x8007005, Facility:Win32, Description: Access is denied, connect to the remote system (RDP) and do the following:
Run dcomcfg | Component Services | Computers | Select My Computer | Action Properties | Default Properties
Ensure that "enable Distributed COM on this computer" is checked.