Folder comparer

Does anyone know of a program to compare the files in a folder to see which ones are missing from one folder or the other.
i'm trying to make sure that a couple porta drives have all the files that my main HD has on it. i'm lazy and don't want to go through 10,000+ files looking. i know i'll screw up someplace. :cry

 

What you need is a sync utility..... SyncToy is a free 'powertoy' available for download from Microsoft for Windows XP and above. I haven't used it personally, but I have friends who use it all the time and love it... Check it out here: http://www.microsoft.com/windowsxp/using/digitalphotography/prophoto/synctoy.mspx

 

I think SyncToy is just going to be the thing i need. not excatly what i was thinkin of but so far i do belive its going to work great for me.