My Ext HDD is malfunctioning for no reason?

Okay, so this is how it started. I had my Android tablet (Acer A500) hooked to my x64 Windows 7 PC, to transfer a file to it. After that, I tried to safety remove it, but since it uses MTP, it was not in the connected devices list, so I accidentally safety removed my Ext HDD, a Seagate 1 TB HDD with a power outlet. Since the PC said it's safe to remove the hardware, i removed the HDD, and my tablet, and hooked the HDD back on, but ever since, my computer says it needs to be formatted... while my tablet that has a USB port, recognizes it and it works fine. I've also tried another computer, running x86 Windows 7, but it doesn't work on that one either. I tried changing USB ports, no game. I tried the USB ports in front my case, and using them causes the computer to say device not is recognized. Please help me, I've got over 700 GB of precious data on my HDD I can't afford to lose. Since in works on Android, I don't think it really needs a format... I also tried a reboot... no dice