I apologize in advance if this is a dumb question. I got sick of burning CDs to back up my files, and decided to buy a couple of USB sticks for important stuff. Well, once I saw the prices and sizes of the sticks, and saw those of external HDs, I calculated that it would be cheaper for me to buy an external, "mobile" hard disk to copy files to. So now I have a 40 GB external HD that's smaller than a postcard, but thicker, and have back ups of all my important files on it (actually, I went overboard and copied almost all of what's on my regular HD, after scanning that for viruses, etc.). So, is it okay to leave it plugged into the USB hub, or should I remove it? I'll probably be backing things up weekly. If I get a virus on my HD (C), can it move to the external HD (E) without my copying files to the latter? Will my computer take longer to boot up with the external HD?