My BookWorld has empty folders

I want to use My Book World as an external drive for my Windows 7 Back up. However My Book World does not come up as an available drive.

I know that MyBook World drive is working as I’ve managed to set up a Windows 8 back up to the drive.

i have tried sorting this through various forums on the internet over a number of occassions with no success so can someone please help me.

Thanks

Traceymuseum