To register for AIM you must go to its web site and fill out some information. It is worth noting that if you are an AOL user, you can use your AOL account with AIM. However, you still must register on the web site. You might want to register for AIM if you are an AOL user if you don't like having AOL open all the time, but would like to receive instant messages while AOL is not running.
You will want to click on the text that says "New Users Click Here" to initiate the registration sequence.
If you are already an AOL member look for the text about already being an AOL member and click there. You will be asked your AOL screen name and your zip code. AOL will e-mail you after you register for AIM (on your AOL e-mail account) you want to respond to that e-mail by hitting reply and typing OK into the reply so that your account will in fact be setup.
If you are not already an AOL member you will be asked to enter information such as a password, screen name, and e-mail address. Enter all this information and click on continue. If your desired screen name is already in use keep trying different ones until you find one that is not. Remember a great deal of screen names are taken because AIM is so popular.
Now that you have registered for AIM click on the button of the AIM installation file that you want. Choose Windows if you are using Windows. This guide will only discuss the installation steps for a Windows version of AIM but the Mac version should be pretty straightforward.
A prompt will come up asking you where you would like to save the AIM installation file. It will be much easier if you save it to the desktop. Do this by clicking on the desktop icon (it looks like a desktop and will say "go to desktop" when you move your mouse over it) then click save.
Now that you have downloaded the file it is time to install AIM and set it up to work with your computer.