External HDD problem

[Andrew]

Well, my device was working perfectly earlier today, but when I was finished using it I unplugged it. Right when I unplugged it I got a 'fail to write' error from Windows, and I thought nothing of it. I don't know if it has to do with my problem. However, my problem is that whenever I try to plug it in again, the light flashes red, but the drive never loads. In addition to that, I can't load any programs if the device is plugged in, and I can't restart either. Nothing works. I can't access the drive at all. If I leave it unplugged, turn off my computer, plug in the device, and try to reboot, it still does not work. My computer cannot reboot at all with the device plugged in.

Things I have tried:
System restore
Turn off computer for 10 seconds
Manually install driver

The problem is still there. My computer somehow recognizes the device because it says it is loaded. However, I can't even 'safely remove' it because it freezes. The instant I pull out the device everything works again. What could be the problem?

 

[Emperor Pan I]

turn it on?

 

[Andrew]

It's USB powered. It automatically turns on when I plug it in. What used to happen was that I would plug it in, and then the drive would automatically start up and I could access the files. Now I plug it in and nothing happens, except the light blinks red (which means it's reading something) and then nothing loads.