Strictly speaking the operating system is the software that controls and manages the computer system but most operating systems also include programs called utilities. Utilities are not essential for the computer to work but either make it easy for the user to use it in some way or provide housekeeping functionality. We can categorise these utilities as follows:
Security is about keeping the computer system safe from hazards. Hazards come in many forms but includes viruses, hackers and spyware. To keep this in perspective though, the most dangerous thing a computer has to face is the users themselves who are likely to accidentally delete files or put them in the wrong place! The backup utility is probably the most important one of them all.
A virus is a program that is installed on a computer without your knowledge or permission with the purpose of doing harm. It includes instructions to replicate automatically on a computer and between computers. Some viruses are just annoying but don’t really do any damage but some viruses will delete and/or change system files so work files are corrupted or the computer becomes unusable.
Antivirus software will protect a computer in three ways:
New viruses are found regularly so it is important that any antivirus software gets regular updates from the internet.
If a computer is connected to the internet it is potentially accessible to anyone else on the internet. If a local area network, such as a school network, is connected to the internet then all the file servers, the email server, the web server and all the computers are potentially accessible. Some people hack “just because they can” but often it is for identity theft or just getting your bank account details so they can empty your account. Occasionally people hack with malicious intent but this is less common.
A firewall blocks access from the internet onto a PC or network. These work using several factor, for example:
A firewall doesn’t just stop unwanted access from the outside world via the internet; it can also stop computers on a network from accessing specific sites or categories of site on the network. This feature is used to stop staff in companies watching the cricket while they should be working or from using social networking sites during work hours. In school you’ll find that many sites have been blocked. Try going to a games website or getting to Facebook on a school a computer and you will probably get a message saying that the site has been blocked. It is the firewall software that stops this traffic getting out of the local area network and onto the internet.
Operating systems like MS Windows have firewall utilities included but you can also buy firewall software separately. Free firewall software can also be downloaded from the internet and many banks provide free firewall software to customers using their internet banking services.
In the image above the firewall is shown defending the network from the unwanted traffic (shown in red).
Programs that secretly record what you do on your computer are called spyware. The purpose of the software is to capture passwords, bank account details and keywords used in internet shopping and banking. These details can then be used to make purchases on the internet.
A spyware protection utility runs in the background on a PC. It detects spyware programs and prevents them installing. It needs to regularly update itself from the internet so it can detect any new threats.
Some spyware is used for legitimate purposes though. Companies can use spyware to track what is happening on an employee’s computer. This is not common and the employee should know it is happening. Parental control software may also use spyware-type scripts.
We take it for granted that we can organise our files into folders and easily move files around within the folder structure. This utility provides a logical view of how the files are organised to make it easier for the user. There are no little yellow folders actually on the disk, just lots of binary!
The file management utility above makes the secondary storage look like a nicely organised filing cabinet but it doesn’t really look like this. Files are stored on the hard disk wherever there is space. If you have a big file it might get split up into sections so it can stored in the available gaps. This isn’t very efficient because the operating system then has to keep track of where all the pieces are. After a while hundreds of files are stored in bits all over the disk. Files have become “fragmented”.
The disk defragmenter should be run to improve the efficiency of the computer. It moves the separate parts of the files around so they can be stored together. This makes them quicker to access. The defragmenter also groups all the free disk space together so files can be stored in one place. The defragmenter utility optimises disk performance.
Note of caution: modern SSD (solid state drives) can not be defragmented as this may in fact damage the drive.
All storage media (disks, memory sticks etc) need formatting. Mostly we buy portable devices already formatted so you don’t have to format a floppy disk or USB memory stick, but hard disks in computers will be formatted by the operating system so they are ready to store files in the way the operating system expects.
This is a small sample of the utility programs packaged in most computer operating systems.