I've use Microtek scanners before. Which scanner does he have? Is he launching the scan via a button on the scanner's quick panel? Does it launch the Microtek scanwizard utility or some other utility? What is he trying to accomplish with scans? faxing, copying or something else.

If its scanwizard, the standard mode sets 4 "purposes" with hardcoded resolutions for each purpose. Changing the purpose, changes the resolution. Advanced lets you choose resolution and other options.

What OS is he using?