Jill,
My Computer is a little over a year old. I have always used the same scanner with USB hookup since I have had it. Another reason I REALLY like the Canon scanner is that it is a very small lightweight scanner. You could even travel with it if you wanted to without any problem. All I have to do to scan off of my laptop is to pull out the USB cord from the back of the scanner & plug it into my laptop. No power supply is needed. Andy - Las Vegas