So even though your co-worker may have emailed a funny video, it's no more safe to open than a video downloaded from a complete stranger. Be safe and scan each and every file you download from the Internet or receive through email regardless of where it came from. 4. Create a barrier between your computer and prying eyes. In most cases, you can double click a file inside this window to use it, or you can select it and drag the file to a folder to view later. Depending on how you elected to install Winzip or StuffIt, you may be able to right-click a .zip or .sit file and have the program extract its contents into a new folder for you. 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. One thing that you certainly don't want to use to remove computer dust is a vacuum cleaner. Take a moment to try and think of a place a business where you didn't see a computer in use. From the small local corner store to the largest hospital, computers are in every gas station, grocery store, bank, restaurant, beauty shop, and doctor's office around. From a consumer's point of view - you may not think that's much to worry about. The last advantage that shareware has over commercial software (but certainly not the least) is its applicability. Plain and simple, shareware is the best bet when you want to keep on top of the latest release of a particular program. Sure, computer stores do their best to keep their inventory up to date, but when you can download version 5.6042 of a shareware program as opposed to buying a commercial 3.0 version from the local computer shop, there's just no comparison. Okay - we're assuming that the reasoning behind hiding extensions is a "user-friendly" one because we just can't come up with any other reason for hiding them. No harm could ever come from seeing an extension, but plenty could be learned from it. Fortunately you have this article to guide you through some of the most common extensions that you'll run into.