If you have installed the Resource kit, do a search on the machine for sysdiff*.* this will pull up the following files: sysdiff.exe, sysdiff.cnt, sysdiff.inf and sysdiff.hlp. If it doesn't then you will need to get the files from microsoft. I believe you can download just the pieces of the resource kit. In any case, without the sysdiff.inf file, you will not be able to run the program.