Problem seeing a MP3 drive in "My Computer"

[#1]

Glad to hear you got it working.
MTP is a real pain, like you I really dont like WMP and when my daughter recently got a new mp3 player that ONLY supported MTP it looked like it was going to be fun!!!
Anyway I looked into linux ( UBUNTU ), put it on an old PC I had lying around and so far I'm ( and more important she is! ) impressed. Rythmbox Music player supported MTP out of the box ( well almost , you just have to activate the MTP plugin ) and its much simpler than WMP , you just drag and drop to the MP3 player. Sound Juicer is pretty good at ripping CD's to MP3 although needs a bit of tweaking to get the speed up to Windows standard but its nice and simple.

[#2]

Thanks Ian for pointing me at the link that has indeed cured it. 
The only annoyance now is that it shows as 2 drives and only one actualy works. Still thats got to better than being forced to use WMP.
Once again the Plusnet forums have proved to be a wonderful tool. 

[#3]

These problem are caused by usb keys in the registry. When you connect a usb device its recorded in the reg and it stays there if it gets corrupted or it loads the wrong driver then next time its plugged in it will once again load the wrong driver. reinstalling drivers sometimes works but often it takes the old driver as its in the reg
There is a free util from MS http://www.ftdichip.com/Resources/Utilities.htm
which shows what devices are connected or were connected with the serial numbers as every device must have a unique serial. If any of them are wrong you can at your own risk edit the keys
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USBSTOR

[#4]

Downloaded the utility and it shows just the one device connected.
In the registry location mentioned there are 2 of the Sansa USB devices shown but it is not possible to delete either of them and they do vanish of their own accord when the MP3 player is unplugged.
Drive E and F still showing when the player is plugged in with only drive E usable. Selecting drive F requests that a disk be inserted.
In the device manager it is possible to disable drive F and it then disappears in my computer but when the player is removed and reinserted the machine insists on setting up the second drive again with drive F coming back. 

[#5]

http://www.nirsoft.net/utils/

Riight what you need to do is plug the device in and find out with the util the serial etc that it thinks is the drive that doesnt work.
now download this free util
http://www.nirsoft.net/utils/usb_devices_view.html
this will let you delete the device and show all devices which have been connected in the past. It will be an old device thats got its knickers in a twist. Thia util lets you do all sort like run a command when a device is pluged in.
Go up a dir as well there are some great utils of all sorts

[#6]

Problem solved
Having tried all the suggestions posted by the good folk of this forum and not getting anywhere I eventually decided to have a look at the manual on the CD that came with the device.
Yes as the old saying goes "If all else fails then read the instructions"
The manual gives the minimum system requirements as :-
• Windows XP SP1+
• Windows Media Player 10+
• CD-ROM drive
• USB 2.0 port required for hi-speed transfer
Now I had stated that the version of Media Player on the laptop was 9.
I decided to put media version 9 player back (system restore to before I started all the tweaking and reg editing etc.) an yes it was back to not seeing the player in my computer.
Next move was to update Media Player to at least 10 and see what happened. (I have version 11 on the main PC that sees the player)
The update skipped 10 and took it straight to version 11 which now makes the laptop see the player without actualy having to use Media Player at all 
So my conclusion is that the software in the media player and not windows was the problem in that the player was looking for version 10 or higher and not seeing it only allowed my old version 9 as the option.
Thanks anyway to all who tried to help