I found this on Windows 7 Forums, but I'm not sure if this pertains to your OS.

Windows 7: Compressed zipped folders error
http://www.sevenforums.com/general-disc ... error.html


If you really need to compress something, I would suggest installing 7-zip or some other file compressor in the mean time.


I also found this, but I'm also not sure if this is the type of error you're experiencing.

Fix Compressed (Zipped) Folder Access Denied Error “Unable to Complete the Operation”
http://www.winhelponline.com/blog/fix-z ... operation/

If would help if you showed the actual error... IIRC you can use Ctrl-C in error message windows and this copies the error message to the clipboard.

Do you get the same error compressing other file formats?

If no files will compress this looks like a system problem. Have you had any other issues recently?

What is the compressed target? This error means the the target file is read-only because either:

• it sits in a device that is read-only (check device for read-only switches)
• it sits in a directory that is read-only (check the directory properties)
• it is marked read-only (check its properties)
• it is locked by some other process (should clear up by rebooting)