As another alternative to selling that machine, we suggest that people disconnect it from the Internet and use it to store personal documents, records, or files. This way, personal data (such as bank statements, store receipts, health records, etc.) is protected from prying viruses or hackers, while the newer machine is used to surf the net. The truth of the matter is that the programs pre-installed are great tools for the beginning computer user. At some point down the road, usage will dictate a need for more powerful applications. We may need a word processor that can convert a document into an HTML page or PDF document. We may need a calculator that solves geometric problems. You'll need a can of compressed air and an anti-static rag to remove stubborn clumps of dust. Hold the can perfectly vertical and spray the fan being careful not to spray the dust off the fan onto other sensitive parts of the computer like circuit boards or inside the motor casing. Wipe up remaining dust with your anti-static rag and then reassemble the computer. " Click "OK" and you'll notice that the files in Windows Explorer show a dot and group of three letters after their names. That dot and group of three letters is known as an "extension," and the extension explains what kind of file it is. A file could be a plain text file, an image, a sound, a video, or program. Orphans are usually files that contain temporary data created by a program, files created by the user, partial files left over from a computer crash, or any other kind of miscellaneous files created for almost any other reason. The problem is that an uninstall program doesn't delete the orphan files it leaves behind because they were never part of the program when it was first installed. Conditions allow a program to perform an action based on the outcome of a previous command.3 Using this type of instruction, we could instruct a program to do one thing if the "x" variable in our latter example turned out to be 7 days, and then do different thing if the variable turned out to be 3 days.