<p>After compiling a simple C++ project using Visual Studio 2008 on vista, everything runs fine on the original vista machine and other vista computers. However, moving it over to an XP box results in an error message: "The application failed to start because the application configuration is incorrect".</p>

<p>What do I have to do so my compiled EXE works on XP and Vista? I had this same problem a few months ago, and just fiddling with some settings on the project fixed it, but I don't remember which ones I changed.</p>

You need to install the runtime redistributable files onto the machine you are trying to run the app on.
The redistributable for 2008 is
here
.
The redistributable for 2005 is
here
.
They can be installed side-by-side, in case you need both.