Event Viewer told me DCOM got error "1068" attempting to start BITS. I wondered what's BITS? I Googled and now I know BITS stands for Background Intelligent Transfer Service. I clicked on the Start Button > Administrative Tools > Component Services > Services Local > Background Inteligent Transfer Service, and then I right clicked on Properties. I found the BITS has three dependencies and they all were running, BITS startup type was Automatic yet its service status was stopped! I told BITS to Start and I was told Error 1068 dependency service failed to start.
Next I tried to find the server specified in Event Viewer ID 10005. I opened Regedit and searched for server ID 4991D34B-0891-4291-83B6-3328366B9097. Regedit did not find anything. It seems BITS has three dependencies: DECOM Service Proess Launcher, RPC Process Launcher, and RPC Endpoint Mapper, and they are all running. Error 1068 is generated because BITS can not communicate with a server that's suppose to be listed in the Registry but isn't .
Event Viewer also reported DistributedCom error 10016. When I Google to findout about CLSID C97FCC79-E628-407D-AE68-407D-AE68-A06AD6D8B4D1 I found it had to do with failure to update Windows. I reviewed my update history and found Microsoft Security Essentials KB 2310138 recently failed to update twice, and now is nolonger listed in available updates.
Next I ran sfc /scannow. Windows Resource Protection didn't find any integrety violations. What should next?