Why Is mscorsvw.exe Running?

My system felt a bit sluggish after starting the installation of a new application and a quick check of the task manager revealed a process named mscorsvw.exe that was running on my system using nearly 40% of my CPU. I never heard about that file before and a quick check on the Internet revealed that it was related to the Microsoft .net Framework.

I never experienced the behavior on my old computer though and it seemed as if the process would not go away on its own. It was there, eating my CPU cycles even after quitting the program installation.

Apparently mscorsvw.exe is precompiling .NET assemblies in the background which can take anywhere from 5 to 10 minutes and then some more for low priority assemblies. So the easiest way to get through it is by sitting it out.

If you want to get rid of it completely immediately you could issue the command ngen.exe executequeueditems. Ngen.exe is located in the Microsoft .net Framework directory in the Windows dir.