Once a month there are 4 maintenance duties that should be performed on every Windows computer.

Scandisk - As often as possible, 1-2 times a month is fine ofr the average user. Found in system tools folder;

start | programs | accessories | system tools.

start | all programs | accessories | system tools.

Disk Defragmentor - As often as possible, 1-2 times a month is fine ofr the average user. Found in system tools folder.

Windows Update - once a month. Open internet explorer. Click the tools menu, choose Windows Update. Most of the time the critical and recommended updates should be downloaded for maximum benefit.

Antivirus Updates - Updating virus definitions should be done 2-4 times a week. Scanning should be set for at least once a month. Process depends on program. Look for automatic settings.