Windows directory comparison tool
I was LOOKING for one for a long time. I finally found one, right on my own system!!
C:\Program Files\Microsoft SDKs\Windows\v6.1\Bin\x64\WinDiff.Exe
There’s also: SyncToy
So it comes with the Windows SDK. Try searching for WinDiff on your computer
If you don’t already have it, then you can get it here.
I use it mostly because I keep redundant copies of entire folders, a lot of the time. For example, when my laptop was going down (lost ability to recharge from wall.. it was gonna go in for repairs!) i made an emergency dump of all the files that were on it. Some of the code files I had several copies of already, so WinDiff expedites the process of being able to blow away entire folders that are completely redundant -

Its pretty neat.

You can also blow out the thing, to see the actual file that is causing the diff