How to undock your creative Zen, or, in fact, undock any MTP device ?
One common issue among portable mp3 devices is that when you plug it on your computer through USB in order to recharge the battery, you're no more able to play the songs stored on it. The device's button stop responding, the device's content is visible and allow you to copy the songs onto your computer, but you can't read the songs directly from your device.

To be able to use your device to play music, you have to unplug it. If you want to play music while the device is recharging, you have to use a standard USB Charger, not a computer.

An other option, described here, is to "undock" the device. The USB port will still be connected to the computer and the device will still recharging, but the device won't be accessible (until you reverse the manipulation) from Windows. On your device, you'll have the exact same behaviour as when you charge it with a USB charger.

On my KU990, no problem, when connected to the computer you have a "Cancel" button that allows you to "undock" it.

On Creative Zen (and, I assume, some other badly designed portable devices), there's no button to "undock" the device, no shortcut, no icon either on Windows. Seems like a dead-end.

However, I found a way (but that may require that you have full rights on your computer) :
Access the device manager by any of the 2 ways below :
* Click on "Start" / "Run", enter "devmgmt.msc" and press enter.
* Right-click on "My Computer", choose "Manage", double-click on Device Management.

Plug your device (if not already done).
You should see a "Portable Devices" line. Double-click on it. Right click on the line corresponding to your device and choose "Disable" and ... Shazzam ... the device is now longer accessible from explorer, your device's buttons are responding again and the device is still charging.

To have your device available again as a MTP device on your PC, just do the same and choose to "Enable" the device.