Whether you run Windows XP, Vista, or 7, you have a few really good ways to cut out the fluff and make your OS run more smoothly, quickly, and efficiently. By turning off unnecessary features and disabling unwanted startup programs, you can get an instant speed boost.
Knock Out the Fat
Windows--yes, even Windows XP--is loaded with effects that take up system resources without delivering meaningful user benefits. If you turn some of these items off, Windows can divert the resources to more useful activities, such as running your programs.
In Windows XP, open the System control panel and click the Advanced tab. Click Settings and then select the radio button marked Adjust for best performance. This will turn off some of the frilly effects, such as drop shadows under your menus, and make Windows a little snappier.
In Vista, start by disabling the resource hog known as the Sidebar. In both Vista and Windows 7, turn off the Aero environment to reclaim some of your PC's lost memory and processor power. To do this, right-click the desktop and choose Personalize from the context menu. In Vista, click Window color and appearance, and then uncheck the box for Enable Transparency. In Windows 7, select the theme labeled Windows 7 Basic.
Shut Down Memory-Hogging Apps
Once you've installed a fair amount of programs on your PC--your "core base" of apps, as it were--you'll want to check that you don't have any unwanted applications running in the background that could slow down your PC. Such programs may be designed to launch when Windows starts up so that you can load their corresponding applications faster. The problem is that they run all the time, regardless of whether you intend to use the parent application.
In Windows 7 or Vista, click Start and type msconfig in the 'Search programs and files' field. Press Enter. In the System Configuration window, select the Startup tab. In the Command column, look for any programs that you don't want to wait for at boot-up time. For example, take iTunes: If you've installed this application, you'll find both iTunesHelper.exe and QTTask.exe. They're unnecessary additions--the former launches when you start iTunes anyway, and the latter merely places a QuickTime icon in the corner of your screen for easy program launching. Uncheck both. Once you've checked all of the programs you want to launch at startup and unchecked the programs you don't, click OK.
In addition to startup programs, you can find services on your PC; Microsoft recommends trimming them as well. Click Start, type services.msc into the search field, and press Enter. Up pops the Services window, a list of options and executables that's even more confusing than the Startup window.
To identify which services to turn off (and which to leave on), check out Black Viper's exhaustive list of Windows 7's services across all of its various editions, along with a list of which services you should modify and how you should set their parameters. Armed with this advice, just double-click on any listed service. You need concern yourself only with the 'Startup type' listing in the screen that appears next. By switching among the Automatic, Manual, and Disabled modes, depending on Black Viper's recommendations, you'll be able to control exactly how services launch--if at all--during the Windows startup process and during your general use of the operating system. Every little bit helps.
Maintain Top Performance
If you want to keep your system fast, clear out your C:\Windows\Temp folder on occasion. Do it as soon as you boot into the OS, or even through Safe Mode, to ensure that you wipe every last unused file from your drive. In the same vein, don't use Windows 7's uninstall function or a program's default uninstall executable to remove an application from your drive. Instead, use the free Revo Uninstaller utility; this awesome application removes programs using their default uninstall routines, but it also goes one step further by scanning your system and Registry to clean away all traces of the program from your hard drive.