I am actually doing a little coding today, woot!  Except, I haven't gotten NANTRunner to run on my Vista 64-bit workstation yet.  I need to use this in order to correctly build the solution.

Running any build target from NANTRunner (even an empty one) was yielding this result:

 Win32Exception: The system cannot find the path specified

By using an empty target in the build file, I ruled out problems with the build script, or accessing files that were part of the build.  So this means that VS or NANTRunner is missing something.

I grabbed a copy of the handy-dandy Process Monitor from SysInternals and applied some filters.  Here's what I narrowed it down to, although it didn't seem suspect to me at first:

vcspawn.exe Path Not Found

I searched the registry and it doesn't look like the path to this file or folder is defined in there, meaning something is hard-coded to this path.  I went to find this file, and found the problem: VS.NET 2003 is not installed under "C:\Program Files".  It's installed under "C:\Program Files (x86)".