Thank you for your reply. I was under the impression that WINE does not have complete one for 64bit yet. Just to be clear, I want to build 64 bit WINE not building 32bit WINE on 64 bits as the following page suggest. http://wiki.winehq.org/WineOn64bit As an exercise, I tried to build WINE test code for 64 bit on Windows. So I grabbed the code and ran 'msvcmaker' to create project files. There I did not see x64 so I pretty much copied the win32 project to create x64 project file but when I tried to build the project such as Kernel32, I got bunch of errors so I decided to post a question first to verify if I am doing the right thing. Please give me some pointers so that I could refer as I tried to build. Thank you.