Just purchased a 1TB WD Passport Ultra and am running it on a Windows 7 Home Edition 64-bit OS. Windows Explorer is not showing one of the folders on the drive. In a CMD window it does not show up with the DIR command either. But, I can use the change directory command and see all my files and folders. If I change back to the root, the folder I was just in doesn't show up again. It's there with all the files; choosing Properties in Windows Explorer shows the correct amount of disc spaced being used. I can use a batch file to backup data from my primary hard drive to this folder so DOS is seeing it. When I use Microsoft Security Essentials to check for a virus, the folder (and files) show they're being checked. Folder is not hidden with the H attribute. The only attribute set on any of the files that can't be seen in Windows Explorer is the A(rchive) attribute which I would expect.