When you bought your computer, it was fast and efficient. Then, bit by bit, things got slower. Programs took longer to launch. Downloads that used to take mere seconds dragged out for minutes -- in some cases, hours. Your system crashed and froze. Games and interactive DVDs began to play like slide shows.

Welcome to Slow Computer Syndrome. Most people blame the problem on spyware, lack of RAM (computer memory), or the age of the PC, and they're mostly wrong if they do.

While spyware is a serious threat, it's rarely the sole reason for waning computer performance. You may have plenty of RAM for your needs, but your PC may be using it inefficiently. As for the age of your hardware, there's no physical reason why it should run any slower than the day you bought it.

So what's really behind all those aggravating slowdowns, crashes, and freezes?

A 2007-2008 sample of over 500,000 computers worldwide shows the top PC speed killers as:

REGISTRY ERRORS, CLUTTER, AND FRAGMENTATION

Your registry stores key data for your Windows operating system, including user profiles and settings for software and hardware.

An error-free Registry is vital to your computer's health. But as you install and uninstall programs, printers, and more, errors and clutter accumulate. Long after you uninstall a program, information about that program will remain in the registry, creating an obstacle during startup.

One PC expert likens this to the process of finding phone numbers in a chaotic address book.

"Suppose you put the names, numbers and addresses of every person you've ever known in your address book. But instead of removing no-longer-current entries, you just keep adding pages and pages of new data. It would take forever to find the number you need, as you wade through huge amounts of useless, out-of-date information."

To make matter worse, as your registry grows it becomes more fragmented. And since the registry has to be loaded into memory from your hard drive every time you start your PC, the more bloated and fragmented your registry is, the longer you'll wait for your PC to boot up.

HOGGING THE STARTER'S POSITION

Many programs load themselves partially whenever you start your PC. This makes them seem more responsive when you launch them, but with so many programs starting at once and tapping system resources, boot times and overall performance suffer. You may want to preload a couple of favorite programs for quick access, but not all those seldom-used utilities queuing up on your taskbar.

BAD INTERNET SETTINGS

90 of all computers have hard drive errors. These degrade performance and may prevent you from saving or retrieving files. Worse, hard drive errors may be a sign of imminent mechanical failure that could cost you all your data.

HANDCUFFING THE PC SPEED KILLERS

Most of the above PC problems can be fixed quickly, easily, and inexpensively with PC Tune-up software that will repair your registry, remove junk files, eliminate malware, defrag your hard drive, boost your internet settings, and prevent non-essential programs from running in the background.

Any PC Tune-up program worth its price should offer at least two levels of control: 1) Advanced options for technical users who want to be able to tweak their settings and get the most out of their performance tools; and 2) Preset, automated system maintenance for the average user who simply wants to keep a computer running fast and problem-free without having to deal with configurations, diagnostics, or even ordinary PC cleanup functionality.