I recently configured a trial Windows Server 2012 R2 VM to start fiddling with it and use it later for other not so important things.
One beautiful winter night, I observed that even if I am not doing single nasty thing on this machine still I see my CPU usage 100%. Whoa, who is eating my cookies?
At first glance in task manger, I found two alien processes gobbling CPU and some RAM
.Net Runtime Optimization Service (also known as mscorsvw.exe)
Microsoft Common Language Run-time native compiler