I have connected my Sansa Clip to my PC using the USB2 ports in the front of the CPU. The Clip screen reads ‘Connected’, but the Clip does not show up as a drive on the ‘My Computer’ screen. I have XP SP2 installed.
The clip is set to the ‘Music’ menu and is fully charged.
Try switching the USB mode on the player to MSC. It should then show up in Windows Explorer under Devices With Removable Storage alongside your CD and/or DVD drives.