New Post: How to specify the specific installation directory

Hello, currently I am using Wix# to make a setup on Windows 8, but I found a issue.

Here is my code segment.
...
Dirs = new[]
{
new Dir(@"PortfolioSurveyor", new Files(@"Files\*")),
new Dir(@"%Desktop%", new ExeFileShortcut("PortfolioSurveyor", @"[INSTALL_DIR]PortfolioSurveyor.exe",""))
},
...
Compiler.BuildMsi(project);

After I ran the msi file on Windows 8, I found all files are installed in the folder E:\PortfolioSurveyor\, actually I would like to install these files in the C:\PortfolioSurveyor. I tried to modify "new Dir(@"PortfolioSurveyor", new Files(@"Files*"))" to "new Dir(@"C:\PortfolioSurveyor", new Files(@"Files*"))", but failed to build. Can you please tell me how to set the installation directory to C:\PortfolioSurveyor?

Thanks,
Redstone