How can I keep these websites from popping up on my computer?

How do you keep your instant messagers from popping up when you turn on your computer?

• Ok Here is my problem. My yahoo. msn, and myspace instant messagers pop up every time I turn on my computer. How do I keep them from popping up? It is causing the virus scan that I have to slow way down and then it takes about an hour to finish the virus scan. Note: The virus scan, I have, runs everytime I turn on my computer because I don't want to get a virus. I don't have the money to pay for another computer. But If anyone knows how to do this could you please please answer this question! I really need your help.

• Answer:

  Go into yahoo, msn, and myspace instant messenger programs and there should be an option that says "preferences" or "settings". Using that option, there should be something that says "automatically run/login at startup" or something like that. That will prevent your programs from running whenever you turn on the computer, and you'll have to run them yourself whenever you want to use the instant messengers.