External HDD issues

I have a 500gb external mybook by western digital. I recently plugged it into my pc to gather some data from it when i realized the icon for it wasnt showing up. so i ignored it for the time being and figured i would come back to it. Later, i go back to it and now it shows up but if i click on it, i get an error saying invalid I/O address. So i disconnect it and connect it to my vista laptop... same problem. ok so i plug it back into my pc and i figure ok i might as well at least format the drive and start it fresh, i dont care so much about the data on it, as i only have maybe around 1 gb used. the icon shows up in the my computer window, if you double click it, the my computer window crashes... if you right click again the my computer window crashes. So now i dont know what to do, i would just like the drive working again, regardless if i lose the current data on it or not. Any assistance would be great!