Your computer, like your car, needs proper maintenance to perform at its best. Knowing your way around your PC and conducting routine repairs will keep it in good working order.

• Know your system. At a minimum, you should know what kind of processor you have, how much random access memory (RAM) is installed, and how big your hard drive is. If you're aware of these vital statistics, you'll be in a better position to troubleshoot problems when programs tap your machine's capabilities.
• Make an emergency boot disk. Before you have problems with your computer, create a startup disk using your original operating system's CD. Save this disk in a safe place for the day -- which you hope will never come -- when your computer has problems booting up from the hard drive.
• Use your system's built-in utilities. Your hard drive stores information by scattering it on the hard drive, and eventually this fragmentation slows down the computer. Run Disk Defragmenter (for Windows) or a similar application periodically to consolidate the data and keep your drive organized. Also, utilities like Disk First Aid for the Mac and ScanDisk for Windows can repair disk problems and make your machine more efficient.
• Use antivirus software. Install an antivirus program, and set it to scan your system regularly. You should also set the application to scan every file you download.
• Back up regularly. Make a habit of backing up all your important files at least once a month. You can back them up manually or with an automatic backup-and-restore program, which does the work for you.
• Don't delete programs manually. Whenever possible, use either your computer's uninstall utility or a separate uninstall program to remove software you no longer need.
• Use good work habits. Shut down your machine properly, and respond to warnings and error messages promptly. You should also keep your machine as clean as possible by periodically opening its case to remove accumulated dust, cleaning your keyboard and removing dust from your mouse.

Your computer vendors will offer service contracts for some additional fee beyond the purchase price. Read Do I Need a Service Contract for My Business Computers? to determine whether this is worth the cost. And, for additional guidance on the actual purchase process, check out How to Buy Computer Equipment for Your Business.