Sorry for my bad English. I am from russia (use google translation).
I use Ccleaner for over 2 years and without thinking clean my the system and registry as it is safe. Once turned on the computer and found that half of the services not working. Long searching for in what could be the problem. It turned out that the registry delete key start the services ("DCOM Server Process Launcher" and "Remote Procedure Call (RPC)").
As we know from the service "Remote Procedure Call (RPC)" depend a lot of other services.
Deleted registry keys are restored from another computer and it worked.
I asked myself what could delete these keys?
And one day running a clean registry and found that it was my Loved Ccleaner. (((