A virus originating from the boot sector of a computer is a boot-sector virus and this nasty devil does its dirty work the moment a computer is turned on. A virus that attaches itself to (infects) other programs is a file virus and activates the moment that an infected program starts. File viruses may also be referred to as parasitic viruses, however should a virus work from both the boot-sector and from an infected program, the virus is then known as a multipartite virus. " A dirty fan doesn't rotate fast enough to keep that motor cool and a completely clogged fan just stops rotating altogether. This causes the computer's motor to work harder - and a harder working motor can raise the electric bill! Worst case scenario: the motor can overheat and stop working as well. The only way to get an MS-DOS computer to do something was to type a command at this prompt and if you can imagine, it was a rather cumbersome way to use a computer. As an example, to load up Microsoft's simple editing program, you had to type the name of the drive that the program was on, the directory that the program was in, and then the name of the program. Although there are too many to list here, Windows provides more than a handful of useful utilities that will monitor system resources, organize files, repair damaged disks, and more. Yet and still, you can easily find similar tools for sale at computer outlets and download libraries. What's going on here? All this is possible from making just a few changes in your computer's current configuration. Your computer's main configurations are housed in Windows Control Panel. Within this small section of Windows, you can make some major changes from the way that your computer looks to the way that your computer responds to the people who use it. Unless the activities on your computer are restricted to pure textual output (plain text files), your computer is going to get filled with a lot of "stuff" - stuff that can overfill a PC's capacity too much for the computer to function well. 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.