Crashes and Freezes-Restarting your Computer
Crashes in your computer is what happens when your computer is contaminated by a virus or it normally happens when the computer has had too many commands at once and it’s trying to attend to all of them in matter of chorology, that is first come first serve.
A Crash can be defined, as when the computer has broken down and it is in other ways no longer operational, normally this is noticed when the computer has come in contact with a computer virus otherwise referred to as worms. The computer can get this be downloaded contaminated documents or files and other things from the Internet. This causes the computer and its programs to be contaminated and thus unreadable by the computer tower itself, sometimes this viruses can causes damages also to the hardware inside the computer tower, thus making it become impossible for the computer to work properly. Your computer may also crash if it is dropped or damages with liquid or any other substance that may affect the suitable function of the computer machine, the functional manual of the computer and should be studied very carefully so as to know what are you should not do to your computer machine
Only a certified computer repairer or technician can handle this kind of fault, this is very important to note as to have this kind of fault completely repaired you need the services of a train hand or personal, trying to solve this problem by yourself or an untrained hand can cause more damages to the computer machine itself and may finally become harder to repair
Here is a list of some viruses and what the do to your system;

Constructor.VBS.Alamar:
This is a script-worm construction tool. It was used to create "Anna Kournikova", "Anthrax" viruses and "Lee", "VBSWG" virus families.
The constructor is able to create worms, which can replicate using e-mail and IRC channels (using mIRC or pIRCh programs). The worms created using this constructor can also:
- start automatically with Windows
- copy itself to system folders
- encrypt their code
- open pre-defined URLs
- show a pre-defines message or picture
- "halt" the operating system

There are more than 10 different versions of this constructor. There are a lot of viruses created by this generator contain bugs, and do not work.
IRC-Worm.Kromber:
This worm Trojan spreads via IRC channels, and is 3584 bytes in size.
When launching, the worm checks for an active IRC client on the victim machine. If it finds this, the worm will send a link to a remote site to all accessible IRC channels by using the /amsg command:
http://www.kromberg.at/[censored]/show.php?f=drunkchicks.jpg LOL
It also attempts to install this link as the name of a channel and comments to it.
If another user clicks on this link, the remote site will be contacted. This site contains a malicious VBS script (which will be detected by Kaspersky Anti-Virus as TrojanDropper.VBS.Inor.h). This will install and launch the worm's executable file, named browsercheck.exe on the victim machine.

Macro.Word97.Titch:

This virus contains only one macro Auto Close and replicates him or herself on document closing. It contain the comments:
An experiment in Macro programming ;)
Minimum stealth, no encryption, No payload, No mail replication
If you had looked you could have found and deleted it but.
You probably never knew it was here!

Win98.Matyas:

This is a primitive, non-memory resident parasitic virus. It searches PE EXE files in the current directory, and then writes itself to the end of the file. While spreading, the virus uses direct calls to the Windows kernel by using hard coded addresses. These addresses are valid only in the Win98 standard edition. As a result, the virus is not able to spread under other Win32 versions. Being run under non-Win98, the virus causes a standard "error in application" message.
The virus does not manifest itself in any way. It contains the text string:
Màtyàs Corvinus kezdettall.
The above three are the know most dangerous viruses and worms that are available in the day to day computer world these can cause very serious or substantial damage to your computer machine, there are a lot more, but you can also prevent a virus from contaminated your computer system by installing a good antivirus software, This software is made to detect and notify you immediately you come in contact with a webpage or your are about you download a file or a program that has been contaminated or encrypted with a virus, with this you can promptly decline to proceed with your download or surf the website. Below are some examples of antivirus software

McAfee antivirus
Norton antivirus
Symantec antivirus
F-secure antivirus
And there are lots more.
Freezing is a computer term that refers to the computer when it automatically stops working, but is still on, in this case what you normally experience is that your mouse is no longer moving and everything that you where doing on the system is still on the monitor without moving, in this case if you were listening to music it will begin to skip in the same track and also if you try to click on any of the programs that you have on your monitor you will hear a bell ringing, this is normally are sign that you have given too many commands to the computer that it is trying to process them, we should always remember that even thou the computer is fast it is still a machine and thus a simply thing like a lot of clicks from the mouse and a lot of click on the monitor can simply cause the computer machine to be slow in processing your commands and thus causes the computer system to freeze. Normally this is not a very serious problem you can simply solve this by only by waiting for some minutes, say 5 for a maximum, this should give the computer enough time to be able to read your commands and act on them, if after this time and still your computer does not automatically de-freezes itself then you can restart the system. Note that if you restart your system you will loss all unsaved materials, and restarting a computer this way is not really the best for the system, in this case you will have to press the start button or the restart button which is normally much smaller that the start button, if you press the start button you will also have to press it again for the system to be on, but if you used the restart button, the computer will automatically restart itself, and it will run a check to search for any damages that the restarting may have caused the computer system.
Note that it is not good to restart your system or off your system with this method, you must try as much as to prevent the above things from occurring on your system and so as to restart and off your computer system the right way THRO THE START MENU!!!!