Sometimes the free software offered with a new scanner is less robust than you may be led to think. Tips for Using Your New Camera Scan directly into the format you want. The scanner is working with the original, so you'll get better tonal quality. And you won't waste time, system resources and hard drive space needlessly creating the colour image. Don't overscan for display.
Massive confusion exists, even among professionals, about the different kinds of resolution.
Images are actually composed of many tiny dots. Remember that increasing resolution doesn't increase the actual size of the image. You just get more dots, not bigger dots. Each dot takes up file space, so the resulting file is about four times larger and could tax your system. And it is likely overkill.