Computer Viruses

Types of computer viruses are:

Macro Viruses: Macro Viruses use commands (macros) embedded in other software to infect and spread to other files viewed by that software. E.g. Word and Excel have macros and macro viruses can spread by exploiting these commands..

Worms: Worms duplicate themselves and use communications such as email to spread. They can look at your email address book and send themselves to users in your address book.

File Viruses: File viruses attach themselves to other software. When the software is run, the virus first loads itself into memory so that in can further infect other files or begin damaging the computer.

Trojan Horses: Trojan Horses are programs that claim to perform a particular function but in fact do something different. E.g. they could infect your computer with a virus or erase your files.

Backdoor Trojans: Backdoor Trojans are programs that allow other computer users to remotely control your computer via a local area network or the Internet. . . . Boot Sector Viruses: Boot Sector Viruses are an older type of virus and not so common. They used to infect a computer's startup program so that the virus would become active as soon as the computer started up.

Adware: Is to internet browsing as spam is to email Adware can profile your online surfing and online shopping habits and or placing annoying pop-up adverts, installing additional IE menu helper bars. Often Adware revolves around targeted advertising based upon the web sites you frequent and you may not even be aware that the pop-ups are not coming from the actual web site visited itself but from the Adware software running locally on your machine. Quite often these applications are installed by stealth or by deliberately misleading users to install software that is not required. Spyware: Is potentially a higher threat than Adware as it often collects user details, such as software installed and often sensitive information such as passwords and even credit card details which are then sent to via the internet to a central collection point. Spyware is often installed covertly or by accident via pop-up windows with active-x controls which report that they are doing something benign whilst secretly installing this malicious software.

Page Hijackers: Are applications that redirect links to specific web pages, such as a request to go to a search engine for example, and instead redirect the web browser to a designated address, related to the initial link but often containing advertising or adware. Whilst not as high a threat as Spyware, it is often a sign that your computer has some spyware or adware components installed on it which will undermine its operation.

The affect of a polymorphic virus on a computer is exactly the same as any other virus. That is, that it is capable of the same processing as any other piece of software.

The name polymorphic or in English "Many Shapes" refers to the virus's programmed ability to alter its own code when replicating itself to avoid detection.

Most simple antivirus programs use a sample of code to match against a suspected file to identify a virus. Changing the code makes detection impossible using this technique.

A more accurate method of locating a virus is to examine the code and programmatically detect what the code does. For instance if within the few lines it instructs the computer to wipe the hard drive it is 99.9% likely that this is malicious. A statistical assessment of the code is made and if the code breaches the chances of being highly malicious, then the code is flagged for removal.

This technology is called Heuristic analysisand is not without it's problems. The trigger level between virus and non-virus can be set too high or low, resulting in false positives or failure to detect malicious software. False positives can be triggered by software that does some to the things that Viruses are likely to do, such as formatter programs or communicating with a centralised server.

Overall the combination of both systems plus a register of known good and bad software is the most effective at detecting virii.

Well since you asked this question you must of used the keys on your laptop/computer! So you must of had the sense to count them...

Total Keys = 84, but it depends on what computer you have....

The answer may vary according to which operating system you use. The Zoom Out functions are generally in the same location(s) as the Zoom In functions.

One way is to click on View in the main toolbar in the upper left hand corner of your screen, and then scroll down to click Zoom. Click on Zoom Out in the sub menu.