Print dialog problem

I need some assistance in fixing a problem with the print dialog box. From any application on my wife's PC (Windows 7 Home Premium) when we try to print using ctrl-P and bring up the print dialog, the list of printers automatically scrolls to the last printer in the list. If you click the dropdown and select a printer (other than the last one), you can see it modifying the list until it selects the last one again. The default printer is the 3rd or 4th out of the list of 8 or so. Any ideas? Harley