But if you take a good look at what's being offered at no cost, you may be in for a big surprise. The quality of today's freeware and open source software created a strong rift among the commercial community and it's literally driving the competition bananas! So much so, that even some well known software development corporations have joined the cause and built a few freeware open source products of their own! Although this software does a pretty good job of removing unwanted programs, it can leave some files behind even after a complete uninstall - files which become orphan files. And it's these orphan files that can really clutter up a hard drive and shorten the life of an otherwise, young and robust PC. 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. When Windows was developed, the need for typing commands was essentially eradicated thanks to the introduction of the point-and-click (mouse) interface. The email messages are often disguised as important messages from well-known online establishments, and they often try to scare their readers into clicking links with threats of closing an account of some sort. Sometimes the links are harmless and attempt to con the reader into volunteering personal information (credit card number), but other times the links attempt to download harmful software onto a computer. One thing that you certainly don't want to use to remove computer dust is a vacuum cleaner. Although using a vacuum cleaner seems to make more sense, the strong suction of a vacuum cleaner can actually spark damaging static electricity or dislodge loose cables. You also don't want to use oil-based cleaners. A powered computer lacking an operating system wouldn't display anything more than a bunch of confusing text messages that describe the computer's boot process. At the very end of this process, the computer looks for an operating system and if not found, it will prompt the user to tell it where it is.