Using your mouse, right-click on the little yellow man, a pop-up menu should appear. Click on "Connect to Netscape AIM..."
A bigger window will appear, click on the "Setup" button.
A fairly large dialog box will appear, click on the "Misc." tab, and make sure "Start Netscape AIM when Windows starts" is unchecked. Click the "OK" button.
The previous window should reappear, click on the "X" button in the upper right corner to close the window.
That's it, the little icon should disappear from your taskbar, and won't
reappear unless you install another copy of Netscape.