What is .NET Runtime Optimization Service and why does this process appear in multiple process and eating my CPU and RAM?

Previously in Windows Server 2012, this process chain can be stopped by ending the process tree, but it seem I can't find the process tree in Windows 8, it appears to be trying to communicate to the internet.

There is currently 10 mscorsvw.exe running on my PC, Whenever I try to end the process, my computer says Access is denied.

What is mscorsvw.exe anyway? what does it used for? and why does it keeps eating my CPU and RAM performance?

Hi RandomguY9000,

Thanks for posting your query on Microsoft Community Forum.

mscorsvw.exe is precompiling .NET assemblies in the background. Once it's done, it will go away. Typically, after you install the .NET Redist, it will be done with the high priority assemblies in 5 to 10 minutes and then will wait until your computer is idle to process the low priority assemblies.

For more information on mscorsvw.exe refer this link:

The task manager in Windows 8 has been modified for better Graphical user Interface. The End process tree is available under the Details tab in the Task manager. For information on features available on the new Windows 8 task manager refer the link:


Hope the information provided help! In case you have any more issues related to Windows Operating system feel free to post and we will be happy to help.

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Last updated October 24, 2020 Views 442,884 Applies to: