I'm very excited 'cause I think this can help a lot of people start messing around with their Zune, so we can finally have some decent hacks on it!
With this, you can have your Zune device back to original status, which means you would totally erase its contents and restore its firmware.
First, make sure your device is on a flat surface and don't move it through the rest of the process.
Then, you have to start performing a common reset process (pressing and holding the Back and Up buttons) and then, as soon as the screen turns blank, you have to press and hold the Back, Left and OK or Middle button.
This will take you through a lot of steps that will leave your Zune fresh and new.
There is one problem that you have to be sure not to run into. Make sure that you didnt change the name of the zunemarketplace.dll file. some people did this to make the zune software run faster. if you did change it, just close the program change it back, and then open it again. it will then auto detect the firmware and then just follow the steps.
I did this and i couldnt really figure out why it wouldnt update the firmware when it asked me to. then i realized i shut off the marketplace by changing the name of the .dll file
You just need to be a little careful. I did this because support told me and it caused more problems than it solved. I could not update the firmware at all and i had tried about everything...so i got them to send a box, but i decided i would try a different computer to see if it would work and it did. So if for some odd reason it doesnt want to put the new firmware on just sync it to a different computer.