You can use the NGEN /show command to check whether things worked ... or you can look in the Global Assembly Cache - normally in C:\WINDOWS\assembly - and you should see your native code version of your program right there with all the .NET Framework assemblies:
Microsoft is serious about NGEN because they're releasing a completely new version with enhanced capability in the soon-to-be-released .NET Framework 2.0. A Microsoft insider, Reid Wilkes, wrote the article "NGen Revs Up Your Performance with Powerful New Features" about it recently in Microsoft MSDN.
In an email exchange with Reid, he commented, " NGEN’s most impressive gain is from NGEN’ing code that is shared by many applications – for instance the .NET Framework class libraries. If you really want to see dramatic slowdown remove the NGEN image for mscorlib and then run several apps."
Uhhhhh ... Maybe not ... unless you're sure you know how to restore the NGEN'ed mscorlib again.
In any case, try out NGEN yourself and see what it does for you.
