Eventually, your PC won't seem to be the speedy workhorse it was when you first plugged it in. To clean it up a bit, restoring its former power and agility, run through this checklist:
Run a virus checker (see Section 15.6.3) and an anti-spyware program (see Section 220.127.116.11) . Viruses and spyware are two big culprits behind a slow PC. Spammers hire virus writers to infect PCs, turning them into " zombies " that churn out spam. Head for CipherTrust's ZombieMeter (www.ciphertrust.com/resources/statistics/zombie.php) for hourly updates on the number of zombie PCs worldwide.
Back up your PC (see Section 15.1) . Your PC should be backing itself up automatically, preserving your data in case of a hard disk crash, accidental deletion, or other computing catastrophes. If you've already installed an automatic backup program, make sure it's still working by checking the date of the most recent backup. If you haven't yet set up a backup program, now's the time.
Free up space by running Disk Cleanup (see Section 9.4) . Your PC needs hard drive space not only for storage, but for virtual memory (see Section 1.6), which lets Windows borrow parts of your PC's hard drive for extra calculations when memory runs low.
Defragment your hard drive (see Section 9.5) . After a few months, the files on your hard drive spread themselves thin. Defragmenting them gathers all their pieces and groups them back together again, making for quicker access.
Uninstall unwanted programs . Head to the Control Panel's Add or Remove Programs area (Start Control Panel Add or Remove Programs) and delete programs you never use. To place your least-used programs at the lists top for easy plucking, click Sort by, and then choose Frequency of Use or Date Last Used.
Weed out any unused network drives (see Section 14.8.5) . Networked drives offer an easy way to access frequently used information by letting you assign a drive letter to a folder on a networked PC. Whenever your PC restarts, it tries to connect with each networked drive, slowing down your PC. This slowdown 's particularly apparent when Windows searches futilely for a network drive that no longer exists. Weed out the outdated , unnecessary ones.