Windows 2003 includes "cmdkey" with the OS.
There is an article about it here:
http://blogs.msdn.com/spatdsg/archive/2006/07/19/manipulate-stored-credentials.aspxI don't know this for sure, but I would speculate there's probably a better than even shot that it'll run under XP if you copy the executable. You may have to grab a DLL or two if it complains about them being missing.