Maybe you have heard about this little trick many times, but here it is again. This will enable you to use your Zune as a portable drive, actually it just shows your Zune in the Windows Explorer window and enables dragging and dropping and stuff, anyway here it is.

In this tweak you will need to use regedit, before you do this, be sure to know what you are doing

1. Make sure your Zune is not plugged in and your the software isn't running.
2. Open regedit, to do this, click start -> run, then type regedit and press enter.
3. Browse to HKEY_LOCAL_MACHINE\System\ControlSet001\Enum\USB\
4. Search for "PortableDeviceNameSpace". This should be contained under the Vid_####&Pid_####\########_-_########_-_########_-_########\Device Parameters within the above ...\USB\ The ##'s listed here will be numbers and letters specific to your Zune.
5. Change the following values: * EnableLegacySupport to 1 * PortableDeviceNameSpaceExcludeFromShell to 0 * ShowInShell to 1
6. Hopefully at this point you can open up "My Computer" and browse your device, though it does NOT show up as a drive letter.You may need to restart your computer.
   Now you can access it as a hard-drive and sync it with the software.

So here it is:

Go Back to Main Menu
Press and Hold Back
No matter what you are doing, doing this will take you all the way back to the Main Menu.

Sleep/Stand-by
Hold Play
This will put your Zune into sleep mode. In this mode, your Zune will slowly drain its battery life but it will keep info such as the song you were playing, what picture you were looking at, etc.

Shutdown
Hold Down + Back
This will completely turn off you Zune, saving you battery life.

Restart/Reboot
Hold Up + Back
This will Restart your Zune, just like a computer.

Reformat Hard drive
Shutdown, Hold Left + Center + Back
While your Zune is off, press this combination and your Zune will tell you that is deleting its content, the way it was when you pulled it out of the box. (didn't quite work for me)

Here's another way:
Restart, Back + Center + Play
Restart you Zune with the combination given above. While your Zune its starting to turn back on, press the combination at the same time and this should revert it the way it was when you first bought it.