That harddrive wouldn't work. There are specific model hard drives you can buy online that can work as a 360 hard drive, but the ones needed aren't seagate (if I remember correctly). Besides, you would need to flash it with a new firmware (hence why you need the specific drive) and also obtain and flash the drive with a certain key so that the xbox reads it properly and such (illegal to obtain online. Must be taken from a legit hard drive. Because of this, you can only read 20gb, 60gb, and 120gb hdd sizes. A higher hdd will read less based on the key and a lower hdd won't work[lower than the key used, I mean])
I think that made sense.