Windows 7 - System image to Flash-Drive?

I do back-up using "Control Panel\All Control Panel Items\Backup and Restore" and select image, but my flashdrive says "The drive is not a valid back-up location".
What is the issue?

thanks

Removable usb device not second internal drive or secondary partition. Windows is rather fussy about that unfortunately. For backups to external usb hard drives you generally need a 3rd party software like the programs often preinstalled on the drives themselves.

Most usb flash drives come with their own programming with some even having a backup a button on included on them if you have the do re' me that is for the higer price tags!

Man i really need a Night Hawk translator. The only restrictions related to backups i have had was due to lack of space, other than that i manged to back up onto anything internal,external, and networked.

Another thing to look at would be the factory partition not being usable where you would need to reformat the drive itself in the disk management. Are you seeing it listed as a drive you can readily access with a drive letter assigned?