Monday, August 1, 2011

How to change computer power supply

Running a PC with power supply fan problems will cook the machine, so if you don’t hear a fan running or hear one starting to die, the only thing to do is to shut down the system. Then head for the computer store and buy a new power supply. They come very cheap these days.

Changing a computer power supply can be done by just about anyone who can operate a screwdriver. Pay attention to the box label, because the only difference in appearance between an AT supply box and an ATX supply box will often be that single letter. Here’s how to change a computer power supply:
1. Unplug the computer.
2. Spend a minute studying what cables go where, including disk drive data cables you might dislodge when untangling the existing power cables.
3. Disconnect the 2-inch wide cable that goes to the motherboard. These have a clip that must be depressed before you can remove them. Then disconnect the power supplies to your various disk drives.
4. Holding the power supply with one hand, remove the four screws that attached it to the case with the other hand. (Motherboards get cranky when heavy metal objects fall on them.)
5. Attach the new power supply and connect the cable to motherboard and disk drive. It takes about 10 minutes.

How to avoid computer viruses

There is a war being fought, often right underneath our very noses. It is a war fought not with guns, or with bombs, but bycomputer viruses, worms and Trojan horses. Computer viruses have been around for a long time. They’re often hidden in your e-mail inbox, among all those offers for quick cash, a bag of diamonds, enlarging this and reducing that, even spam telling you how to get rid of spam.

A worm is a type of computer virus that generally spreads and replicates itself without relying on any actions on the part of a computer user. A Trojan horse masquerades as a benign program, sometimes one that claims to get rid of viruses, when in truth it inserts a virus into your computer.

Virus attacks haven’t attracted much notice from mainstream news media, although that has begun to change. Over the past years, several viruses of varying types, such as the “Blaster” worm virus, made national and international headlines. Law enforcement has historically had a tough time dealing with cases like these. It’s tough to track down computer hackers.

In many cases, damage to individual computer users in virus attacks is minimal. Many simply exist to propagate themselves, ordering the infected machine to spread the virus to as many other systems as the computer can find. Some merely display irritating messages on your screen, tantamount to someone getting in your face and giving you the raspberry.

Some, however, can corrupt critical files that will cripple your computer, and wipe away irreplaceable data. Also, when a virus like “Blaster” comes about, which spreads with alarming speed, it can overload servers and bring entire sections of the Internet to a halt. That’s why it is very important to learn how to avoid computer viruses.

Here’s the bottom line. If you own a computer and use the Internet, you need virus protection to avoid computer viruses. It is becoming progressively easier to become infected. Computers running Microsoft Windows-based operating systems are the big targets, partly because they use the most common operating system, and also because Windows – along with its component programs – are often the most vulnerable.

One thing is to purchase an antivirus program, such as Symantec’s Norton Antivirus or McAfee’s VirusScan, which will scan incoming e-mail and downloaded files, as well as searching your computer’s hard drives for lurking viruses. This is the first step in avoiding computer viruses, but merely buying and installing one of those programs isn’t enough. Each of those programs gives you a “subscription” to new virus definitions, which must be downloaded on a regular basis in order to avoid the newest threats.

If you use Microsoft programs such as Internet Explorer and the e-mail program Outlook or Outlook Express, you need to keep on top of Microsoft’s security updates, which have become more and more frequent. Point your Web browser to windowsupdate.microsoft.com, but be warned. If it’s been a while since you bought your computer or updated your version of Windows, you’ll have a lot of data to download. If you have a dial-up modem connection to the Internet, leave it running overnight.

Apple Macintosh computers don’t present as tempting a target to hackers and virus writers because they represent only a fraction of operating computers, which works in Mac users’ favor, since there are comparatively few computer viruses that are written to attack Macintoshes.

Also, a good rule of thumb to follow is that if you receive a file you don’t recognize, delete it immediately. Treat it as you would a ticking package – don’t even think of opening it. Even so, getting an antivirus program should be a priority for anyone who uses the Internet.

source : http://www.howy.org

How to read PDF

Historically, there was a need to be able to “pass” documents around the Internet and have them retain their layout exactly as the author intended. Adobe developed in the early 1990s a formatting language called PDF (portable document format) that allowed authors to do just that.

The key to the success of this format was to have the recipient be able to view the document without a lot of hassle. So, while the software that allowed the author to build PDF files was quite costly, the “reader” software was free and available to anyone off the Internet.

Before the pdf reader, people would send Microsoft Word documents if they wanted to do something fancy. Unfortunately, that required the recipient to have Microsoft Word installed on their computer to read it. Also, if the exact font was not used, then the recipient computer would substitute a different font and the layout would get all messed up. This is still a problem when sending Word documents.

Microsoft has a free Viewer that you can download from their site which does allow you to view but not change Word documents. There is a security hazard with Word (and the other Office applications) due to the fact that they can have embedded macros. These macros are small powerful programs that can do almost anything on the computer and have been the source of viruses entering computers. So, if you have the option, always send PDF files instead of a Word document as it is safer.

Adobe reader software has become such a standard, that many computer manufacturers bundle it with their new machines. The PDF format has become the method for creating owners manuals, government documents and instructional documents. Not to leave a good thing alone, Adobe has constantly embellished the standard that now it can accept data entry, play audio and video, and allow linkages to Internet sites. This added functionality has taken its toll on performance and size. What was a nimble little butterfly has now turned into a B-57 bomber. All those added capabilities have made Adobe Reader a prime target for the security hackers to attack.

Once thought indestructible, Adobe now has to update the product quite regularly against new and vicious security attacks that can cripple innocent users’ computers. Boo-hoo! So when Adobe wants to popup a message and update its reader, let its will be done.

There is an alternative to read pdf files. Just go www.foxitsoftware.com and choose the button to download the free Foxit reader. Also, there is a free “printer driver” called PrimoPDF that when installed, acts like another printer to your computer. So when you print a Word document or Excel Spreadsheet, you can choose “PrimoPDP” and have it generate a PDF file instead of sending the document to the printer.

source : http://www.howy.org

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