External Hard Drive Problem

Hello, I'm having a problem with my Western Digital External Hard Drive. It seems to be working fine on PS3 and 360 but it doesn't work on my PC. When I first start up the computer autoplay comes up and takes a while then nothing happens and I can see it on my computer but every time I click on it it just asks me to format it?? and when I go to format it says the drive can't be formatted. I have never had this problem before with it as it's pretty new. I would just take it back but there's stuff on there that I need. Anyone know of a solution?