Windows 7: error 0x80070091?

I borrowed my friend external HDD, i transfer the files but they did not transfer correctly they left the folders but none of the files, so now i try to delete the folders & I get this error message?

Hi,
A few questions.
1. Was your friends external HD formatted NTFS with any security like bitlocker?
2. Can you actually see the directories on the external HD?
3. Take Ownership?
4. Have you tried copying smaller files to test before copying a whole bunch.
5. Is this a USB Drive? Do you have the latest drivers for it or did you just plug it in?

Hope to hear form you soon unless you find the solution.

Can you try this on the external HD

Run "chkdsk /f" in Command Prompt

• Make sure virus protection allows this action. It may complain about a registry change.
• Allow chkdsk to complete. It takes a long time. Then it reboots.
• Don't forget the "/f" The "/f" tells the program to fix problems it finds

1. it was locked, but he gave me the password
2.yes
3.what is take ownership?
4.no
5.yes it is usb, and i just plugged it in