"restore to factory settings" not working

SanDisk MP3 players Sansa® Fuze™
#1

Hi, I have a Sansa Fuze that’s not being recognized by any PCs (all running on XP Pro Sp2). It appears to work perfectly otherwise.

I’ve tried to reset it to the factoryDownload Freewaresettings, but when I follow the instructions through the interface (i.e., SETTINGS–>SYSTEM SETTINGS—>etc.) to do that nothing happens. I get the red warning, choose “yes” and and am sent to language selection (then region), but none of my files are removed. So I’m assuming it’s not working.

Is there another way to do this?

Also, does anyone have a working link for the Microsoft MTP Porting Kit? The one that comes up on their site at the moment is broken.

Thanks.

P.S. Here is the error message I’m getting in XP, if it makes any difference:

One of the USB devices attached to this computer has malfunctioned, and Windows does not recognize it.
The location of the device is shown in bold type.
USB Root Hub (2 ports)
  Unknown Device [in bold]
  Unused Port

#2

Settings/System Settings/Format wipes the unit. 

Restore Factory Settings just changes the defaults.

#3

Do you know how to switch usb modes? Try going into the settings menu, and see if either modes work.

PS: Restore Factory Settings only wipes away radio preferences, equalizer settings, and the language your player will use. It’s a  pointless function, if you ask me.