Making Windows XP run faster/better
Too many programs running!
This may seem a bit risky to those of you who haven't delved into this portion of your machine. I assure you, this is 100% safe.
To start, click Start -> Run and type msconfig into the blank space and punch enter.
That's going to bring up the System Configuration Utility.
Select the top right tab, which should be labeled Startup.
That tab will display (almost) everything running at startup. Uncheck EVERYTHING.
I know, that sounds risky. But there are two important facts about the items in that list:
A VAST majority of them are unnecessary - meaning that NOT running them will NOT adversely affect your computer. NOT running them will quite often POSITIVELY affect your computer.
The important ones are going to re-check themselves anyway. Anti-virus software typically watch for that and re-enable themselves as a defense mechanism.
After you've done this, reboot your computer. Some programs like browsers may take a bit longer to come up the first time, but after that, the PC will run as good or better than the day you purchased it. Windows may ask you if you want to run the system config at every startup. Simply check the box that says no (or whichever option you're given that means no) and click okay.
Of course the potential risk here is that you disabled something you actually need. This will just take time to figure out. If your scanner, or modem, or video capture card, or certain software, stop working, you just need to go back in and figure out which item in that list you need to re-enable to make it work. It's usually fairly intuitive but not always. This means most of those essential components will add themselves back to the startup.
I do suggest cleaning the registry and defragmenting after following these steps. You may want to re-enable your antivirus yourself. Just open your task manager (control-alt-delete [ONCE only]) to see whether those programs are running in the background.
Windows 7 and 8
The very same methods can be used with other Windows OS. Some differences exist, though: The area that you want to go into is called System Configuration. You can still go to Startup, and select "Selective Startup". After that, everything remains the same.
It's important to note the differences between "services" and "startup". Unless you know exactly what you're doing, stay out of "boot". Only the most advanced user should ever adjust these settings. Reversing certain mistakes can be a harrowing experience.
One note, though: I've had trouble with Windows 7 (and I refuse to use 8!) actually adding some of my hardware drivers back. If this happens to you, trace back your steps and add those services or startup items back in.
If you're at all unsure of any of these steps, just don't do this. While I've learned a lot about computers and software, this us not my job, and I'm NOT an expert. So, if you break your machine, don't blame me. Following these instructions to the T will definitely work.