I tried to install CU3 on a 2012 RTM server and after installation the Health Service will not start. It was installed by Windows Update as I figured Microsoft would not push it there unless tested. 

I get the following errors in the OpsMgr Log: 

Event ID: 20056: Failed to initialize the IPC channels for other processes to communicate. The HealthService might fail to start

Event ID:2000: The Management Group MG failed to start.  The error message is 0x80131501(0x80131501).  A previous message with more detail may have been logged.

Data Access Service and Configuration Service are running fine. Anyone else seen this or have an idea on how to solve it?