You could even block instant messaging and email from anyone who isn't a fellow AOL user. Other tools available online operate similar to the way that AOL's Parental Control settings work, however no collection of tools could replace the reinforcement of mom and dad. Never let your children speak with strangers and never leave them alone at the computer unattended. Through Display Properties, a user can change the background of the Windows Desktop, add a screensaver, change the overall color scheme and fonts of Windows, and adjust a computer's color depth and/or resolution (screen area). Not just a bunch of preference settings, display properties help individuals who have to deal with visual problems. The problem is that while upgrading a computer is always an option, technology advances so fast that newer products (such as memory chips, new drives, etc.) aren't always compatible with the machines that we own. This is a common occurrence when newer pieces of hardware require the programming of a newer operating system. The two most popular software programs used to compress and decompress files are Winzip and StuffIt respectively. There are other programs that do the same thing and there are even programs that can compress and decompress files for both the Windows and the Mac system. However since Winzip and StuffIt are the most popular, we will assume you will use either one to compress and decompress your own files. The above illustrations were just a couple of examples of how far computer technology has grown, and how far we've pushed "user-friendliness" to its limit. Eventually, the keyboard and mouse will have to play a role when computer newbies have to work with one as a cash register, as a hotel booking program, or as a library's catalog system. Now imagine having to type these long commands every time that you wanted to start a program. Yikes! That's one of the reasons why batch files became so popular. Batch files are small text-based documents that contain a bunch of these commands on their own lines. When executed, they would process each command without the user having to type each and every one of them.