Compare directories on Windows

I am manipulating a whole bunch of files and placing them in a different directory. What I need to do now is find out which files are in the original directory that aren't in the output directory (the problem is being processed by a dozen computers). Is there any script I can run on Windows that will display this?

Use WinDiff. It comes with Visual Studio and Platform SDK and can be downloaded separately. It's mainly to compare files, but it also allows you to recursively compare folders.

In PowerShell:

$d1 = get-childitem -path $dir1 -recurse 
$d2 = get-childitem -path $dir2 -recurse 
compare-object $d1 $d2 

If you are looking for a manual process and have visual studio installed, then you can use windiff.exe to show the differences.

I tend to use PathSync