The minimum requirements differ from scanner to scanner. Check the requirements on the box or ask a local dealer. Depending on the scanner that you buy, it may need or come with a scanner card to plug into your computer. Although scanners usually come with their own drivers for Windows and an image program, they are usually low quality products. It would be useful to have another image processing software package to manipulate graphics.
Some downloadable software packages out there can access the scanner through their own program.