external hard drive

Hi out there in computer space,
I have a 80 gig ext hard drive that once was running ok with xp home, now its not when it is plugged in xp sees the device as in I hear the bong you get when you plug in a usb device the hard drive runs for a ninute and I see the red ligth that was on b4 to say the drive is running, if I look in “MY COMPUTER” I do not see the drive, if I look in divice manager it is there.
should anyone have any advice they can pass on to me I will be greatfull

Cheers peter