I know this sounds simplistic, but I only access the 770's "hard drive" through the cable, or backwards with Bluetooth. If I want to transfer files, I usually let my 770 control the access to my PC. By this, I mean, I surf the files on my PC from the File Manager on the 770, via Bluetooth.

Remember that the closer to the root on your PC, that you set your Bluetooth share, the more of your PC you can see from the 770. By this, I mean, you can even set the Bluetooth share location to be the root of your PC drive, e.g., C:\. Then you could navigate down the entire hard drive of your PC, wirelessly, you know?

For example, if I am at work, and I download an eBook from the web, I simply save it to the Bluetooth share folder. Then I can connect to the PC with the 770's File Manager and drag it to my 770, and I am done.

Or course, if you want to bulk-load files to the 770, you can always use the cable to connect the 770 to your PC, and let it work like an external hard drive.