Q. My computer has gotten slower and slower at doing basic things like booting up and running multiple programs at once. How do I improve its performance without spending any money?

A: You're wise to try to fix this problem yourself, for free. There are a few things you can do to make your computer feel more like the brilliant multitasking machine you want it to be and less like the wheezer it's turned into.

Let's start by setting aside one thing that a lot of people try but we won't recommend here. It's called overclocking, and it involves tweaking your PC's hardware settings to make the central processor or system memory run faster than their manufacturers officially intended. It can get tricky.

Besides, unless you're running nuclear simulations or are a huge video game player, your standard home PC probably should be fast enough for what you need. The problem isn't in the hardware. It's in all the software that's gotten larded onto it.

So here are some simple things to do to gain more control.

- Reduce the programs that automatically launch at startup. Windows offers a few ways to do this; one easy way is to click icons for programs on the taskbar, which most people have on the bottom of the screen. If you select the icons for instant-messaging programs like AOL's AIM service, look for a chance to adjust "options" or "settings." Find the box that tells the program to automatically begin running at startup, and unclick it. And next time you download a new piece of software, check the default installation choices carefully, and make sure you really want something to begin running at startup.

- Cut down on add-ons. You don't have to run every aspect of a useful program. For example, Google Desktop is great at indexing and finding the contents of your computer, but it also likes to display a sidebar full of "applets" with news headlines or stock quotes. If you use this and the computer goes into slo-mo, see what happens if you turn off the sidebar. Click on the swirly Google Desktop icon and instead of "sidebar," "deskbar" or "floating deskbar" select "none."

- Change your Web browser or the way you use it. Browsers can get balky if you have too many tabs or windows open at once, especially if some of the sites you're visiting have interactive content like video or dynamically updating sports scores. Tests by The Associated Press have shown that people can do better if they switch away from Microsoft Corp.'s Internet Explorer 7. The open-source Firefox browser is a good alternative, as is Google Chrome and the next version of Internet Explorer, IE 8, although technically the latter two are still in "beta" test mode and not all sites work well with them yet. If you use Firefox, be sure to activate a program that blocks Flash video from running on Web sites you have open but are not currently viewing. To get this performance enhancement, go to addons.mozilla.org and search for "Flashblock."

- Post your photos or videos at moments when you can leave the computer and do something else. Internet access providers generally let you download data much faster than you can upload it. Attaching your photo to an e-mail or sending it to an image-sharing Web site eats up a lot of time and computer resources that get in the way of trying to do other, basic tasks.

- Try Windows PCs' built-in performance-assistance tools. One involves defragmenting your hard drive. "Defragging" cleans up stray bits of data that have found their way into various places on the hard disk and can't be accessed in the most efficient way. Go into "Programs" or "All Programs" in the Start menu, then click open "Accessories," followed by "System Tools," and then select "Disk Defragmenter." It can't hurt, though we've found the performance improvements from defragging to be barely noticeable. You might get better results from another option in the same "System Tools" menu: "Disk Cleanup." This deletes temporary Internet files and other junk you don't really need.

"A PC does require some maintenance," says Bill Calder, a spokesman for Intel Corp., whose chips are the brains in most personal computers. "You don't need to be a rocket scientist to do it."