Before I start, let me say that this is not my problem, it's a friend's.
So I don't have the computer available now, nor do I have any more info unless I call and ask him.

He has a Creative Zen Vision M 30Gb music player, and a HP NX6125 laptop with XP Pro.
A few weeks ago, it suddenly stopped working, for no apparent reason.  He says he made no changes, he just plugged it in one day and it was fine, the next day this happened.
When he plugs it into a USB port, he gets the found NEW hardware wizard.  If he follows it through, he gets a message saying there was a problem installing the hardware.
If he cancels the wizard and uses the disk that came with the player, it says it INSTALLS fine, but does the same thing next TIME he plugs it in.
Whichever way he installs the player, it does not work - it charges the battery and the screen lights up, but it cannot be seen by My Computer, WMP10 or Creative MediaSource.
It used to say "docked" on the screen and show up fine.
The same player works fine on my laptop.
So far, apart from the above, he has tried uninstalling the player from device manager, with the same results.

Does anyone have any ideas why this would be happening or what to do about it?
He needs his player working ASAP.
Thanks in advance.
Calum.