If you see it in Windows as the F drive, that is good. So, I wonder why you are not able to follow the procedure to re-assign the drive letter. If Windows sees the iPod's disk, it should appear in Disk Management.
Try shutting down the computer, and disconnecting all USB devices, including hub. Start up the computer with only standard keyboard and mouse connected, if normally used. Do this to Reset the shuffle
http://support.apple.com/kb/HT1655
Run iTunes. Connect shuffle to a direct USB port on the computer (the one you use with your iPod touch).