My backup drive always lights up busy. bios will see it but windows wont. When I connect via usb or esata or directly to a pc, it will not let the pc boot from either the boot drive or a cd drive. When the external drive is on and connected to the pc, windows wont turn off the pc. If I disconnect, windows will shut off normally. Win disc management will see the enclosure but not the drive. Its a seagate st3250410as. Does anyone know what the problem is?
Sounds like you have a problem with the drive. I assume that you've got the drive plugged into a wall outlet to provide power to it, right?
If possible, I'd remove the drive from the case and hook it up directly to your motherboard power and SATA ports to see if the drive itself is working OK. If it is, you can buy a different enclosure for the drive.