I just purchased another 60 gb external hard drive. I've never really gave it much thought, but sometimes when i plug my usb hard drive in my laptop, it will give me a message saying there isn't enough power. So i just turn of the notebook, plug my drive in, then boot up. All is good. The question i have is does it matter if you plug in your usb external drives while the computer is running, or should you always make sure that your pc is power is off before you connect it. Also, how long would be too long to leave your usb drive plugged in and running. I can't help but think that when i haven't used it in about a week or so and it's still plugged in running that it's creating wear and tear that isn't necessary. Thanks, Kyle.