Here’s the dirty little secret about most registry cleaners and defragmentation tools: they don’t work that well. Despite their boasting, most programs that claim to automatically “optimize” your system or “clean out the junk” generally leave users virtually unchanged system performance. And unless there’s a direct reason to suspect heavy disk fragmentation (if there is, try a third-party defrag tool rather than Vista’s built-in option), defragmentation usually provides little more than a placebo effect.

However, there are a few simple, straightforward procedures you can use to legitimately boost the performance of Windows Vista, which, although nearing its second service pack, is still sluggish for many users.

Here’s a list of the top 10 methods for delivering a genuine, noticeable speed boost to Vista without purchasing new hardware:

1. Check your WEI What’s a WEI you might ask? It’s the Windows Experience Index–a score, calculated by Windows Vista, that roughly indicates your computer’s capabilities. To see your score, click Start, right-click Computer, then click Properties. In the system tab, click Windows Experience Index.

Theoretically, a higher score means better performance. You can get a higher score by adding RAM, upgrading your graphics card, or replacing your processor. However, you can also sometimes boost your score by simply updating your drivers. The fastest way to do this: click the Start button, start typing Update, then click Windows Update.

Next check the manufacturer websites for any of the installed hardware components you know of: graphics cards, motherboards, or just the manufacturer of your computer. Install any pertinent updates then restart your computer.

Now come back to the Windows Experience Index score window and click “Update my score.” If your score went up, you should notice a performance boost.

2. Make sure your processor setting isn’t short-changing you Open the control panel, then navigate to Power Options. Choose “Change Plan Settings,” then click on “Change Advanced power Settings,” and finally select Processor Power Management. Unless you are trying to conserve battery power, try changing your maximum processor state to 100%. Many manufacturers ship systems with a lower setting.

3. Turn off or modify indexing; update search Windows Vista uses a persistent indexing mechanism to catalog new or changed files on your disk for search purposes. Unfortunately, the indexing process can eat significant CPU cycles and memory, especially if files are changed often. First, try modifying indexing settings to exclude certain folders, especially those in which files are changed often (browser caches, system files, etc.). Open the control panel then navigate to System and Maintenance > Indexing Options. Remove locations that are modified often, as well as those in which you are unlikely to search.

Also, you will likely want to update to Windows Search 4.0, which can provide a dramatic performance boost when you actually do want to search.

4. Switch your antivirus software Antivirus software can be a performance boon, protecting your system against things that can slow it down, or a bust, actually slowing down your system itself. If you’re still using the antivirus software that shipped with your system, try switching to one of the many free alternatives and tweaking your antivirus settings. Some restrictions can severely impact performance and do not deliver an real security. For instance, although there is some risk involved, you can try excluding certain frequently used or memory-intensive processes from your antivirus protection list. Never do this for Web browsers or other network-connected applications.

avast!, AVG and NOD32 deliver solid mixes of performance and protection.

5. Check for unnecessary services Click the Start button, type services.msc and press return. Here you’ll find a bevy of services, processes and programs–some critical, some not. Disabling certain items, especially those that launch at startup, can provide a real speed boost, but don’t get trigger happy; disabling the wrong process can result in stability problems and other issues.

To disable a service, right-click it, then select properties and choose “Disable.” This article provides a decent rundown of services and their purposes. When in doubt, thoroughly inspect the description of a service.