Passport works on desktop with XP, wont install drivers on laptop with vista

I got this from a friend of mine he didnt have a disk or anything for it, though it works fine on my desktop but when i go to plug it into my laptop it tries to find drivers but always fails. I have tried to download and intsall drivers myself and failed aswell. I am not sure if they are even the right ones because when i pull the device up in device manager it doesnt even recognize manufacturer or anything for it. Basicly only thing i know about it is its small red WD on front and its got numbers on back i will list them.

WD P/N : WD2500MERC-00 0709A

S/N: [Delete]

R/N: A7B

Now that i think about it I could most likely get its information from my desktop since it reads it just fine. Any ideas pelase help it has been driving me crazy for awhile.

If this a really old external it may not be compatible with Vista. Vista had a lot of hardware problems.

Joe