DoIT for Students recommends that all students install security software on their computer.
DoIT for Students recommends Microsoft Security Essentails, a free anti-virus product from Microsoft that can be found here:
http://www.microsoft.com/security_essentials/
Please note that any antivirus product you may currently have will need to be uninstalled before installing Microsoft Security Essentials. To remove old antivirus software, head to the Control Panel and the Programs section to remove it from your computer.
DoIT for Students recommends Malwarebytes, a free malware removal tool that is very powerful and removes most infections. It can be found here at Download.com.
Both of these products are free and are compatible with Windows XP/Vista/7.