For Windows users:
When you start up your computer, a handful of programs get loaded and run in the background. Some are useful, some are not. If the number of programs running is very large, it will significantly slow down boot times and use up valuable system resources (memory, processing cycles). Look at the system tray (bottom right hand corner of your screen). If there are more than a few icons next to your clock, then you can probably shutdown some of them. Here’s how:
If you have WindowsXP, Me, or 98, then click the Start button, Choose "Run…", type "msconfig" into the box and hit enter. On the window that opens, choose the "Startup" tab. This will show a list of all the programs that get started when you start Windows. You can click the checkboxes to turn their startup behavior on and off. How do you know what each one does? The easiest way to know is to type the name of the program into Google and see what the program does. After choosing the programs to turn off, click "OK". The computer will tell you the changes will take effect after you restart. There is no need to restart now. The next time you restart, you will receive a message warning you that you have chosen to use a Selective startup. You can choose not to show that message again. If all goes well you should have a faster bootup time. If some programs seem to not work properly, you can repeat the procedure and turn those helper programs back on.
I also highly recommend a little utility program that helps you to do this. It is called Starter. Find it here. After downloading and installing this program, open it up. It will take you to a similar looking list of programs as you saw in msconfig. It allows you easily turn programs on and off at startup. It also will allow you to save configurations so that you can easily restore the settings if you break something.