Windows 7 Backup Feature

I have a Passport Ultra and I would like to use Windows 7 Backup on my external hard drive. The system recognizes the hard drive and allowed me to create a system image and store it on the drive. When I go to Windows Backup it shows the drive, but won’t allow me to use it. It says it’s disconnected, but it shows a date of the last backup and the next backup. Could you please tell me why this is happening?

Hello, see if the following links helps.