The problem is that Visual Stuiod re-create lib everytime. How can I make MSVS does not re-create? I don't know why MSVS create some kind of project's "lib" file whenever I press F5 to debug application. I just converted a solution file from 2005 to 2010. And this problem is occured. [ Revival ] 1.Build solution. 2.Debug 3.Stop debug 4.No source code change 5.Debug (re-create lib) I think that re-creation lib is not necessary. Re-creation lib file takes just a second. But it is little annoying. I'm in desperate need of your help.