Hi, I'm a newbie of Vtune software. my application is a 64bit windows software, write by c# & C; when i use Vtune to tuning it, i confused by following problems: 1why there are two same library? (mscorlib.dll & mscorlib.ni.dll) 2Can i use ngen.exe to generate symbols for native image library? please ref the picture for detail; Best regards. Henry Ho.