Windows 7 error: Location is not available or Item not found

Question

I'm using windows 7 ultimate. I have a directory on a 1TB external usb drive called "1976 T.N.T". I am neither able to access this directory nor am I able to delete it. When I double click to access it windows says -
Message Title: "Location is not available"
Message Text: J:\Music\Library\Rock-Metal\ACDC\1976 T.N.T refers to a location that is unavailable. It could be on a hard drive on this computer.or on a network. Check to make sure that the disk is properly inserted, or that you are connected to the Internet
or your network and then try again. If it still cannot be located the information might have been moved to a different location.
When I try to delete it windows says -
Message Title: Item Not Found
Message Text: Could not find this item.
This item is no longer located in J:\Music\Library\Rock-Metal\ACDC. Verify the item's location and try again.
I have tried the following -
1. Deleting file using command prompt but that doesn't work
2. Check disk with both options "File system errors" and "Bad sector recovery" selected - it does not report any errors and the problem persists
3. Rebooting the computer
4. Disconnecting the drive and connecting it to my xp pro laptop (messages on xp are slightly different but to the same effect)
Any suggestions short of formatting the drive will be appreciated.

Answer 1

The cause of this is as follows:
The directories in question were created or last modified by a process other than Windows Explorer. This process created a directory name with a space at the end. When you created a duplicate directory, the exact directory name you created was therefore
not exactly the same; it had no space on the end. That is why both directories with the apparent same name could coexist.
Note: if you attempt to create a directory from within Windows Explorer with a space on the end, the process explorer.exe is designed to prevent this from happening. That's why it's never usually an issue.
To reproduce this problem, you could do the following:
1) Create C:\foo
2) Create C:\bar
3) Use Robocopy to create the erroneous directory using the following command:
robocopy "C:\foo" C:\bar" /E
Notice that I missed the first double-quote on the target location. Robocopy should have responded with an error, but due to the way it interpreted my input, it didn't.
Now you will see a directory called C:\foo\bar
Except this directory is actually: "bar " - the word "bar" with a space on the end.
Now try deleting C:\foo altogether. It won't because there is a directory underneath it that has an invalid name.
Now try entering C:\foo, and creating a second directory called "bar". This will work, and there will appear to be two directories named "bar".
But this time you can go up a level and delete "C:\foo".
Put it down to a bug in Windows, a bug in Robocopy, whatever you like! That's the reason though...