May be helpful: Ngen.exe executequeueditems
Post 5 on MS07-040 issues (see Ngen Patch):
By Steve Coffman
Posted Friday 13th July 2007 01:13 GMT
Luckily my system didn’t go haywire after installing the .NET patch, but afterwords I noticed a new process running called mscorsvw.exe. I run my XP system pretty lean and mean and have disabled all non-essential services and processes (I only have a total of 4 non-MS processes and 4 non-MS services that load on startup…) so I was curious as to what it was. Doing a quick web search, it turns out it is a background compiler for .NET assemblies. Theoretically it is supposed to compile the assemblies during idle time (it is set to lowest priority) but mine wasn’t doing much of anything while my system was just idling. The info I found says if you run the command ngen.exe executequeueditems from the .NET folder (mine happened to be in C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727) it will force it to process everything it has in the queue. I gave it a try, and it worked great – it compiled something like 97 assemblies, and after a reboot the mscorsvw process is no longer running.
BTW, if the process is running at 100% CPU usage after you execute the command, that indicates that the .NET framework is corrupt and should be reinstalled. Check out http://searchwincomputing.techtarget.com/tip/0,289483,sid68_gci1225866,00.html for more info on the process.