Can't Scan To My Computer Using Usb - 6505 Xerox

My 6505 Xerox printer/copier/scanner was scanning to my computer through USB fine for months, although once in a while when I put paper in the tray and tried to scan to my computer, it would not scan at first. The screen on the Xerox display would look like it was thinking, or waiting for a program to initiate. Dots would scroll accross the screen. Then, while the dots were still scrolling accross the Xerox display screen I would click on my computer's start menu, and then click on the Express Scan Manager, then a small screen would pop up on my computer monitor and simultaneously my scanner would start scanning. I would clike OK on the program that popped up, and all was good.Then skip to a week ago, and when I tried to scan to my computer, the dots started scrolling accross my Xerox diplay screen, and it looked like it was thinking again, so I clicked on the Express Scan Manager, like I normally do, and for a second, it looked like it was trying to open the small screen that normally pops up on my monitor, but after several seconds, it stopped trying to open that program, and nothing happened. My Xerox in turn errored out, and it wouldn't scan.Any thoughts?