Had we a nickel for every time a friend, loved one, or random stranger asked us, "What's slowing down my PC?" we could shutter PCWorld and retire to live comfortably on a small, secluded island. But since no such deluge of small coins seems likely, we'll instead outline some methods you can use to troubleshoot unexpected slowness on your PC, free of charge.

Of course, systems differ, software differs, and your specific system's history is unique, so we aren't in a position to pinpoint the source of your problem. Nevertheless, we can give you some generally helpful hints that you can use to dig out of the mess.

Know Your Hardware

It's important to know what hardware your desktop or laptop PC contains. Don't run for a screwdriver or some third-party program (though CPU-Z is pretty handy for the nitty-gritty details) to figure this out: If you built your PC, you should know what's in it. If you bought it, look up the manufacturer specs online. Easy enough, right?

Familiarity with your PC's components helps you troubleshoot speed issues in two major ways. First, it gives you a chance to recognize by sight or sound when something isn't right. Is your computer emitting a strange noise? Maybe it's a struggling fan, or the "click of death" from a hard drive approaching extinction. Do you hearing a random sound from your speakers whenever you try to perform a specific task within Windows? Does your optical drive make a different sound than your used to hearing when it spins its disc? Keen listening skills can't give you answers right off the bat, but they can help you notice that a problem may be afoot.

Second, understanding your hardware will allow you to target issues that you can look up within Windows itself. For example, suppose that you pull up the Task Manager (press Ctrl-Alt-Delete, and select Task Manager) and discover that your system has only has 2GB of physical RAM listed in the Performance tab. But you also know from checking the specs that your system shipped with 4GB of RAM. Conclusion: Perhaps your sudden slowdown is the result of a bad stick of memory. You can apply similar reasoning to an underclocked CPU, to missing capacity (or drives) within a storage array, and even to the absence of specific components that you'd expect to see on your system (Lost your optical drive? Maybe your motherboard is on its last legs, and its demise is affecting your overall performance in some way.)

Stay on Top of Updates

If could choose between a free 1998 model car or a free 2011 edition of the same vehicle, which would you pick? The newer one, obviously--but for some reason many people don't employ the same logic when it comes to their PC's operating system, software, and hardware.

There are three major kinds of updates you can apply to your PC. Software updates are newer versions of the applications currently installed on your computer; some companies notify you of their availability via tiny icons in your taskbar or via pop-up windows within the application itself. Driver updates are the specific pieces of software that allow Windows to communicate with one of your system's hardware devices. Firmware updates relate to application-level software programs stored on a device's memory--the "brains" of your camera or wireless router, for example.

Why are these important? Because the updates that affect your software and hardware could influence your system's performance on various tasks. Remember the slow file transfers that plagued the release version of Windows Vista? Microsoft corrected them with its huge Service Pack 1 update for the OS. Another example: More than 15 driver updates have been released for the Radeon HD 5870 graphics board since its official launch in September 2009; and depending on the game being played, these can boost your system's frame rates by 2 to 38 percent.

Before you start worrying about exotic methods of bringing a sluggish computer up to speed, make sure that your system's hardware and software have the latest available updates. When you fire up the latest versions of each, you may find that the problem vanishes.

Speed Up With the Scientific Method

If you've noticed a sudden slowdown when using a particular application or when performing some specific PC process, review what you've done since the last time the program performed perfectly.

If your Web browser's ability to render pages has slowed to a crawl, for example, pay attention to how many tabs you have open and what those tabs contain. Have you installed any add-ons to your browser lately? Did your computer crash during a recent Internet surfing sessions (suggesting that it may be time for you to fully uninstall/reinstall your browser)?

If you want to multitask or play games, but your system is delivering significantly worse speeds than you're accustomed to seeing, look for causes methodically. Is an application (or errant program) running in the background and eating up your system resources? Pull up Windows' task manager and check your available memory and CPU usage. Are you background-downloading a huge file on Steam or uTorrent that's sapping your bandwidth and making your online gaming stuttery? Have you not booted up your system for some time, and is it automatically running various virus scans, file backups, Windows updates, and who knows what else? Check, check, check!

And don't forget Occam's razor: When multiple explanations are possible, the simplest one is the most likely to be correct. In this case of system slowdowns, the likeliest culprit is you. What have you done that might make your system act sluggish? And short of a full system reinstall (or Windows System Restore), what can you do to reverse your most recent actions?

Let Windows Help You

Before you run out and plunk down your hard-earned cash for software apps that promise to speed up your system (FYI: they don't), consider using the free diagnostics tools within Windows Vista or Windows 7.

First, consult the 'Performance Information and Tools' section in the Control Panel. Within it, you'll find an Advanced link that links to all of the operating system's flashier performance-related utilities. To compare the Windows-dictated speed of your system in its original, brand-new incarnation with Windows' assessment of your system's performance now, rerun the Windows Experience Index.

Windows' built-in Event Viewer takes you behind the OS curtain to see what Windows has recorded as a warning, error, or critical issue. These records can be difficult or impossible to decipher, depending on the problem at hand, but they may be able to help you troubleshoot the situation or at least tell a better-informed advisor what your issues might be.

The Performance Monitor is a real-time method for looking at how your PC is using its hardware and system resources. Though it's more descriptive than diagnostic, it might point you in the right direction to identify your system's performance bottleneck.T o cut to the chase, fire up Windows' official System Health Report. The OS will scan your activity for 60 seconds and then offer you suggestions for maximizing your system's capabilities.

The ideal quick-fix supertool would scan your system, eliminate the junk that's that's bogging it down, and give you a fresh and speedy computing environment that would last for months to come. Technically, that operation exists; it's called a wipe and reinstall of your Windows OS. Short of this drastic measure, however, there's no one-size-fits-all solution for transforming a sluggish system into a speedy one. The underlying problem could be a hardware issue, a lack-of-hardware issue, a software issue, an operating system issue, or a random unknown issue.

But by following the tips and suggestions in this article, you'll have some tricks and tools to use in tackling a system that's running slow. You may not have the ideal fix for every situation, but at least you'll know how and where to look for one.