When choosing "Debugging Tools for Windows - Local Debugger" (the "Windows Debugger") as debugging engine, I am unable to run/debug a program. It used to work with the Beta, but not with the RC.
I upgraded from the Beta to the RC (as the MSDN page stated that upgrading is possible). I don't know if it works with a fresh install of the RC, and I cannot compare it to a Beta install because I don't have them (anymore) and cannot really reinstall because of time constraints.
I ran Process Monitor alongside and could not find anything accessing any Windows Debugger files. It looks as if VS2012 treats the Windows Debugger as not being present (although as said, the Process Monitor doesn't show anything accessing/checking any Windows Debugger files).