Having some form of Internet Security Software (such as Anti-Virus) to protect you and your computer or notebook is a necessity.
Windows 7 has security software already installed called Windows Defender, this is NOT an Anti-Virus program but an Anti-Spyware program which runs automatically when the PC / Notebook is turned on. It gives some protection from undesirable software that can be downloaded from the Internet. This program is very limited in what it can do or the overall protection it gives.
It is recommended to have a full Anti-Virus program installed - some work with Defender; some replace it. There are many different programs available, some of which are free. These include:
Avast: download here.
AVG Free Edition: download here.
Microsoft Security Essentials: download here.
Windows 8.x comes with a new version of Defender installed, this is an Anti-Virus program not just an Anti-Spyware program.
It is recommended only to have one anti-virus program on your PC / notebook, otherwise the programs can start conflicting with each other and may fail to work properly, or slow your system down.
Applies to: