A trivial example is that with MAC, users can't easily turn "Secret" into "Unclassified" data. However, MAC can actually do much more than that.

Search the net for McAfree and Associates and download their anti-virus shareware program or other Anti-Virus program. Mac users find an appropriate anti-virus program.

To download a graphic to your computer, either right click on the graphic if you're using a PC, or hold the mouse down on the graphic if you're using a Mac.

When your computer was built, its maker configured the BIOS to work correctly with your machine's specific processor and memory setup.

Should you care if your machine crashes?

Invest in and maintain "hot spares" - machines that can be placed into service quickly in the event that a similar machine is disabled.

These EXE files are the output of compilers. They contain executables - machine-readable programs translated from human-readable programs.

The C program is the human-readable form, while the executable that comes out of the compiler is the machine-readable and executable form.

Every time you use a domain name, you use the Internet's DNS servers to translate the human-readable domain name into the machine-readable IP address.

A macro is a scripted series of commands taking fairly complex action at the touch of a few keys.

To simplify complicated procedures, many applications allow you to create a script of commands that the application can run. This script is known as a macro.

Excel files may contain macros, thus turning XLS files from data into programs.

Each mailbox is a single file that can contain multiple messages.

It shows you a list of all of the messages in your mailbox by displaying the message headers.

Reboot your server and check if a user can access her or his mailbox from an Internet browser and also from a mail user agent such as Outlook Express.

This collection of Frequently Asked Questions (FAQs) and answers has been compiled over a period of years, seeing which questions people ask about firewalls in such fora as Usenet, mailing lists, and Web sites.

You can sign up to get email, newsletters or ezines by joining a mailing list.

If you want to be informed of updates fill out the evaluation at the end and subscribe to GrassRootsDesign's mailing list.

Mainframe - In the early days of computing, mainframes were huge computers that could fill an entire room or even a whole floor!

Unix, VMS and mainframe operating systems, such as MVS, are examples of multi-user operating systems.

In the old days, to make a remote connection, you dialed into a PBX or terminal server to connect to a mainframe or minicomputer as a dumb terminal.

In the younger days of the internet, malware was an exercise in technical skill, in beating the security companies and showing off prowess to peers by creating an infection.

Malware is any software program or any component such as a plugin or an ActiveX control that can exploit a bug or a vulnerability, or cause undesirable system behavior or impede desired behavior in and of itself.

Computer viruses have been around almost as long as there have been computers. But these days, writing malware is no longer exclusively the domain of a few socially maladjusted computer nerds.

A hash function is a one-way function mapping a key (be it numeric or string) to some number that is going to be the bucket number.

In general, one cannot guarantee the mapping between IP address and a particular country.

Q: What is IP? A: Internet Protocol. It's the mapping system of the internet and local networks (intranets).

In short markup language is just a set of rules that define how we add meaning to areas of a document.

it means that you design your HTML document visually, as if you were using a word processor, instead of writing the markup tags in a plain - text file and imagining what the resulting page will look like.

XML tags are custom-defined thus enabling the generation of domain specific markup languages for diverse fields such as vector graphics, mathematics, music and technical documentation.

Each entry in a routing table contains a field for the mask to be used with that entry as well as a field for the next hop.

Part of this service provides the requisite IP address and subnet mask to each PC connected to the network.

So, they invented CIDR addressing and routing that uses a mask to delineate the boundary between prefix and suffix.

As an example, let's look at an imaginary small system with 1 megabyte (1,000 kilobytes) of RAM.

As the names imply, megabit refers to individual bits, while megabyte refers to 8-bit units.

Normally, this value is entered in MB (Megabyte).

Memory - This is very fast storage used to hold data. It has to be fast because it connects directly to the microprocessor. There are several specific types of memory in a computer

Most systems use non-parity memory because it's less expensive. Check your system board documentation for the type memory it supports.

For example, Windows XP and UNIX can have dozens of background processes running to handle the network, memory management, disk management, virus checking and so on.

No conspiracy, no need to buy memory, unless you only have 4M of RAM. Buying memory does not fix the "system resources" problem, because its size is fixed at 128K, no matter how much physical memory is installed.

Older computers came with 512 KB of memory which could be expanded to a maximum of 640 KB.

Assuming there is adequate CPU and memory compute power available to process queries, the disk array plus the I/O channel bandwidth hold the keys to improved performance.

Menus are the most common way of interacting or controlling your software.

Right clicking on any part of your desktop brings up a context menu that displays everything that you can possibly do under the context you are in.

In Internet Explorer choose "Organize Favorites" from the Favorites menu.

Previous - Assuming you have a message displayed in the message window, this button will allow you to backup to the previous message. (The one above it)

Instead, remain calm, and, if possible, note down what you were doing immediately before the crash occurred. Also take a note of any error messages that appear on the screen.

My PC begins to start up, but then it displays a message saying that it s unable to find hard disk.

When you send a message to someone it leaves your computer and travels first to your Service Provider, from there your email may travel through several other HOST computers until it reaches its final destination.

When posting a new message you are given the option of entering a title for that message.

Messages appear as threads, which means that an initial topic is posted and then users can add their comments or replies to it.

A microcontroller is a complete system, consisting of the CPU (computing unit/microprocessor), the programming memory (FLASH or EPROM), working memory (RAM) and in/output on a chip.

Also inside the mouse are a switch for each button, and a microcontroller which interpret the signals from the sensors and the switches, using its firmware program to translate them into packets of data which are sent to the PC.

The 8051, being a communications-oriented microcontroller, gives the user the ability to access a number of bit variables.

Both systems are further equipped with x2 56.6-Kbps telephony modems, Cypress's MegaPhone telephony software, stand-up microphones, and Gateway's Home Gallery (with productivity, reference, game, and edutainment titles).

If you don't have a microphone, check out your sound card to see if it has a plug-in jack for a microphone.

Microphone - for the input of voice in place of using the keyboard and mouse.

Some microprocessors have two levels of cache built right into the chip. In this case, the motherboard cache -- the cache that exists between the microprocessor and main system memory

A microprocessor can move data from one memory location to another.

The microprocessor "brain" of the computer system is called the central processing unit. Everything that a computer does is overseen by the CPU.

They can operate in a single-user mode, such as in the case of strictly being a "workstation" (desktop PC), or they can run in multi-user mode to operate as a server.

If a word is chronically misunderstood, use the training mode to teach the software to recognize it for what it is.

Even when electrical equipment is in sleep or standby mode, it's still using a small amount of energy and the government is keen to reduce this even further.

By connecting a router to your dial-up, DSL or cable modem, you can also allow multiple computers to share one connection to the Internet.

There are two basic types of computers connected to the Internet, Hosts and Clients. Clients are machines which access the Internet on a part time basis. They have no permanent connection to the Internet, but instead are capable of hooking to the Internet via a dial up modem, or some similar method.

A modem is used to translate information transferred through telephone lines or cable.

Before doing it, connect all of the external peripherals to the system. This includes the mouse, the keyboard, and the monitor.

The monitor shows information on the screen when you type.

This machine does not include a monitor, but the company's $999 K5 system--which mirrors a classic Pentium/166--ships with a 14-inch CRT.

The movement of the mouse over a flat surface is mirrored by a pointer on the monitor screen.

Extending this concept, "hypermedia" lets you click on something with your mouse and bring up not only text, but also graphics, sound, and animation.

This minitower is accompanied by a wireless mouse (which operates flawlessly at a distance of up to 15 feet), a USB color scanner, a programmable keyboard, and an antenna that receives wireless Internet feeds.