Screen shots of the defragmentation process are displayed below:
The screen shot above shows the result of the process.
Antivirus
Antivirus software prevents and removes Viruses, Worms and Trojans from the computer. Most of the antivirus software comes with built in spyware, adware and malware removal tools.
Antivirus software uses different methods to detect viruses; Signature based detection, Malicious activity detection and Heuristic based detection. Signature based detection is the most common way of antivirus and other malware detection. The software traces the virus by spotting the signature. The software manufactures collect profiles and signature information of the virus in the form of DAT files. These files will be downloaded by the antivirus software through updates and will be used to detect new malwares. This makes it essential to keep the antivirus software up-to-date and to run virus scans periodically.
Firewall
Firewall is a utility designed to prevent unauthorised access to from a private network. It prevents unauthorised internet users from accessing private networks connected to the internet. All the packet data entering and leaving the computer is examined when it passes through the firewall and will be blocked if the packet data do not meet the security criteria. Firewalls build a protective environment around computers that are connected to a network.
Firewall uses four different types of techniques to block unauthorised access. They are:
Packet Filter : Packet filter scans each packet of data entering or leaving a network and block them if they are not based on the user-defined rules. This kind of filtering is an effective method to prevent unauthorised access.
Application Gateway : Application gateway applies security measures to applications like FTP and Telnet Servers. This is another effective firewall technique, but it really affects the performance of the network.
Circuit-Level Gateway: Circuit-level Gateway applies mechanisms when a TCP connection is established. Once the connection is made packets can flow between hosts without further checking.
Proxy Server : This technique is used to intercept all messages entering and leaving the network. The proxy server hides the real network address.
Formatting
Formatting is the process of preparing a hard disk or a storage medium to store data. Formatting a disk involves two major process: High Level formatting and Low Level formatting.
Physical formatting(low-level)
Low-level formatting is the process of outlining the position of tracks and sector on hard-drives and other storage media. All the data in a drive will be lost permanently after a low-level formatting is done. A low-level formatting is generally done by the BIOS rather than the Operating System.
Logical formatting (high-level)
High-level formatting is the process of setting up an empty file system on the disk and installing a boot sector. As this process takes only a little time it is commonly known as Quick Format. In this process the disk also have the option to scan the entire disk for potential defects which may take several hours depending on the size of the medium.
Below is a screen shot of a Quick Formatting.
Disk Cleanup
The Disk Cleanup tool helps to free up space on the hard disk by searching disk for files that can safely delete. You can choose to delete some or all of the files. Disk cleanup tool can be used to perform the following task to free up space in a hard-drive.
- Remove temporary Internet files.
- Remove downloaded program files. For example, ActiveX controls and Java applets that are downloaded from the Internet.
- Empty the Recycle Bin.
- Remove Windows temporary files.
- Remove optional Windows components that you are not using.
- Remove installed programs that you no longer use.
References:
BTEC National- Information Technology Practitioners Book 1 (2nd edition) - Heinemann Publications
http://www.pcguide.com/ref/hdd/geom/formatHigh-c.html
http://www.pcguide.com/ref/hdd/geom/formatLow-c.html
http://www.webopedia.com/TERM/f/firewall.html
References:
BTEC National- Information Technology Practitioners Book 1 (2nd edition) - Heinemann Publications
http://www.pcguide.com/ref/hdd/geom/formatHigh-c.html
http://www.pcguide.com/ref/hdd/geom/formatLow-c.html
http://www.webopedia.com/TERM/f/firewall.html
References:
BTEC National- Information Technology Practitioners Book 1 (2nd edition) - Heinemann Publications
http://www.pcguide.com/ref/hdd/geom/formatHigh-c.html
http://www.pcguide.com/ref/hdd/geom/formatLow-c.html
http://www.webopedia.com/TERM/f/firewall.html
