Sorry if this is a repeat but I've searched high and low and can't find any specific answer to my problem.

Here's what happened:

I reformatted an iPod nano 4g to windows because I needed the use of data transfer between my mb pro and a windows pc. Worked fine and I used it as a hard disk to transfer files between the two platforms.

But now I cannot get it back to mac ipod mode. When I plug it in, it appears on the desktop as a hard disk. Also iTunes opens, but the device is NOT recognized and I can't do anything with it through iTunes.

I have already tried iPod restore, and the buttons for restore etc. all remain faded, i.e. iPod restore does not recognize the device either.

I have tried in disk mode and also tried running the diagnostic tests on the device.

Any ideas how I can bright this thing back into line and use it as a mac ipod?