This is more like a nuisance and could be that I just don't know the right way to do this.   I have several backup drives that contain folders with hundreds of files in each.  Most are identical as they are just dated backups done 3 months apart. 

With the huge increase in drive size I have been asked to put all the contents together onto a single drive. Copying folder A on a backup drive into the folder A on the Main drive.  Normally, I get the message that the file already exists do I want to overwrite or skip.  Since the files are identical I could just say overwrite and let it run.  But it takes a LOT longer to do that than to say skip.  Then when done delete the folder, files and all from the backup drive But there are many copies of these backups so I have to do this until all the folders are only on the one main drive, then make a single backup.

I was wondering if there is a command line switch that would say IF the file already exists on the target drive then delete it from the one you are copying from saving me having to go back and delete all these folders and files. 

Something that would >copy from A to B and if the file is already on B then delete it from A. 

Thanks .. I will probably feel foolish when someone tells me that is a normal  command line switch

Sorry, just saw your reply.
 :)
My job here takes me from editing html on their websites to programming the database on the PPH file server, to editing photos in CS4, to writing scripts to fix things that probably don't need fixing.

When this issue popped up, it was just in sheer desperation since they now want to change the Wi-Fi passwords on different Access points on a regular basis (not a bad idea, security wise considering employee turnover) and in some cases having to do it remotely ( Yes, this  is on the off chance that one of the out-of-Towner's shows up and cannot get into the Wi-Fi)  But if I can do it once on one system, export all four Wi-Fi profiles to XMLS files combine them with a loader in a batch file and load them all with one click .. THAT would save a lot of time.  
I never could figure out why MS wrote that export setup the way they did and then tried to hide the fact it was there at all (tiny blue text easy to miss).  When I found out it took 1 flash-drive per XML...

I should have know the "old ways"  would be the answer.  I never even considered it.   Now I can email out the weekly update as a zipped script to all the users.  
(They don't have a "real" network. Just a workgroup with 3 or 4 servers in it. I cant enforce domain controls on anyone)

Many thanks
Sorry for the double post, I found you there to get here.  Plan on giving it a try tonight.  Wonder if it still performs the same on Windows 8.

PS:  I did find another way but it was Extreme to say the least.  I found a utility made for Servers to deploy over a network that I had to reconfigure to work standalone.  I did it one time, it worked, but  would never want to have to do it weekly due to a changed password.  I believe it was using the MS CMAK tool.  It even lets me pre-map the network drive connections (needed if doing it to a new system)

Yes, both of those are things I do now, but sometimes when on a desperate search for something specific, I cast a wide net when I have time to look, and then later try each utility I found to see if it would solve the problem.  Often this leads to unexpected finds that are totally off topic but still pique my interest enough to download them too.
Maybe two days later I have time to sort through it all and go back to the sites they came from to get a better idea of what each does and even research the file when possible before installing it to test.

A "Download Log" of what came from where might come in handy even years later.  It is definitely something I would keep for as long as possible for reference.

Many of these even come from right here :)  So.. I know my way back.  But some are not even published widely in US and finding them again means following that same exact path to figure out where I was when I found it.

A program to capture and save the internet address you are on when you click download would give you an easy way back to where the file came from.  I appreciate your ideas.  Those are the same ways I do it now and it may be all there is.