My Toshiba hard drive doesn't work on Windows machines At first I was struggling to get my Toshiba Hard drive to appear (so I could use it) on my MacBook Pro (as I wanted to put all my photos, iMovie videos etc on there) so I eventually found a way by going to my settings and clicking time Machine and so on. Now that everything from my MacBook Pro is on the Toshiba hard drive, I plugged it into a Windows laptop (so I could put my photos etc on there) and it doesn't even pop up so I am unable to access my photos etc on there and put them on the Windows laptop, but when I plug it back into my MacBook Pro it shows the hard drive with all my pictures etc on there!
If you're using Time Machine on the disk, the disk is Mac OS Extended formatted which can't be read by Windows without additional software.

You can use the Boot Camp drivers which integrates HFS read/write into Explorer.


http://support.apple.com/kb/DL830


Alternatively, you can use HFSExplorer:


  HFSExplorer is an application that can read Mac-formatted hard disks and disk images.
  It can read the file systems HFS (Mac OS Standard), HFS+ (Mac OS Extended) and HFSX (Mac OS Extended with case sensitive file names).