How to get Visual Studio to open instead of Mono?

I went to edit > external tools > browsed for vs express.
I get file path VS> Common7 > IDE > vsdiag_regwcf.exe .This last file is what I think the problem is. Can i get some help?

you are looking in Program Files, right?

Look in ProgramFiles(x86):

C:\Program Files (x86)\Microsoft Visual Studio 10.0\Common7\IDE\devenv.exe

I’m pretty sure the file you need is:
[VS path]\Common7\IDE\devenv.exe

Visual Studio Express doesn’t work with Unity. You can open the csproj file manually in VS Express, but you can’t integrate it in Unity. You need Visual Studio pro for this.

The express version’s path is:


but as i said, it won’t work with Unity.