ICQ runs on your desktop and takes very minimal space and it doesn't hog up connection transfers so you can easily still browse the net without concerning yourself of speed. The only negative thing I have to say about ICQ is that sometimes, during peak days and hours, you may not be able to connect to ICQ servers. Keep trying however, it usually doesn't take too long to connect. There are so many more functions and the uses are endless. I highly recommend visiting their website and reading more then downloading it and registering to join the rest of the 1.7 million users already using the function.
Installation is a breeze and very user friendly.
A help file is included with the product as well as online support.