How to disable mscorsvw.exe from startup

I have a program called mscorsvw.exe that always runs at startup and it runs about 4 ngen.exe files along with it. This really lags my startup time to about another 5-10 seconds. Anyway to disable it or why this is happening?

It happens because .NET tries to compile its files.

Here is a tutorial on how to disable a start up file http://www.sevenforums.com/tutorials/1401-startup-programs-change.html

However myself I use a program Autoruns by Sysinternals/Microsoft.
I think it is easier. You just start this program, look for crapware and untick it.

Or you can use this trick here
and spend some time by letting it finish what it wants for the first and the last time.
After that it should not do that again.

Alright I used both the Sysinternals program and the trick you sent. Mscorsvw.exe doesnt run at startup anymore but ngen.exe still does for a second or two. What does that mean?

Have you ever let it finish what it needs to do, or have you been killing it in task Manager? Also if you haven't seen it might want to give this a quick read,

What is mscorsvw.exe and why is it eating up my CPU? What is this new CLR Optimization Service? - David Notario's WebLog - Site Home - MSDN Blogs

Yeah I did the second thing and let it finish compiling but it still doesnt go away. About 5 ngen.exe starts up and ends in about 2 seconds when the comp starts.

Don't worry about it then.

With Soluto you can delay the start or kill it (may not be healthy though).

On this same subject of MSCORSVW.EXE...

Just yesterday I applied some Windows Updates. And among them were a number of updates to the .NET components.

Since yesterday, I've seen the well-known and much described system of CPU usage shooting up (with corresponding fan increases to cool the very busy CPU, and associated fan noise). And looking in TASKMGR it's always MSCORSVW.EXE which is the culprit here, apparently doing what it wants to do.

It may be in the background, and it may be at low priority, but it's still requiring 100% CPU and it still has the same effect.


I took the recommended course of action as described in this blog, running ngen.exe in a command prompt window to let it do the rest of its compiles. Took a few minutes, but eventually it finished.

Looking at the relevant directories before I started, it was apparent that something had been modifed in two of the .NET directories, obviously from the Windows Update, and that these were the queued compiles being processed by NGEN.EXE in the background:

03/24/2011 09:42 PM <DIR> v1.0.3705
03/24/2011 09:42 PM <DIR> v1.1.4322
06/15/2011 06:24 PM <DIR> v2.0.50727
11/21/2010 12:06 AM <DIR> v3.0
11/20/2010 08:31 PM <DIR> v3.5
06/15/2011 06:29 PM <DIR> v4.0.30319


And sure enough, now that I've gone ahead and finished all of the "queued items" using the foreground solution trick, I no longer have this 100% CPU issue from the MSCORSVW.EXE service.

It's still shown in services of TASKMGR (though it may not be present any longer if I were to re-boot, which I haven't yet), but at least it's no longer awakening every so often to eat CPU and spin-up my fans. Quite a relief.

dsperber said:

It may be in the background, and it may be at low priority, but it's still requiring 100% CPU and it still has the same effect.

Click to expand...

Background / low priority on process threads only means they'll throttle if other higher-priority processes come up during the next context switch, and those will get priority for more time than they usually would over lower-priority threads. However, you can still end up with something at low priority chewing up all the CPU if the system thinks the CPU time is available and not in demand by anythig else higher priority. You probably know that already, but it bears repeating anyway.

Updated info on mscorsvw

Microsoft has an updated post that might help you and others.

Wondering why mscorsvw.exe has high CPU usage? You can speed it up.

richlander said:

Microsoft has an updated post that might help you and others.

Wondering why mscorsvw.exe has high CPU usage? You can speed it up.

Click to expand...

Ran across this issue this morning. Ran the updates which included about 15 .NET updates and when the computer restarted it went mad. svchost, task Manager and mscorsvw all grab a piece of the CPU and it went mental at 100% CPU usage for about 30 min, so with no end in sight I did a bit of googling and came across the above link which has a script you can download and run in order to speed up what 'mscorsvw' is doing.

Downloaded the script [its a command script that will auto close after it finishes], ran it, minimized it and let it do it's thing.

Seemed to be working as mscorsvw was generally using about 20% CPU but this script made it hog about 50%. Needless to say it took another 30 -40 min and it finally finished and the CPU usage was restored back to its normal range.

If you run into this, give it a try.

Not sure if it would help, but maybe run a few [3 or 4] of these .NET updates each day as oppose to a whole bunch in one go might help avoid excessive 'mscorsvw' activity.

Thanks for giving that script a try, Maco88.

We batch up updates as part of the monthly Patch Tuesday. Many/most system admins want the ability to plan for updates and prefer the monthly cadence that we use. There is no perfect answer, but that's why you see batching of updates. It also turns out that the batching results in less ngen compilation overall, so that's a benefit.