If you're downloading files (especially e-mail) from the Net, then you should have some form of Virus Protection on your machine, learn how to use it and keep the virus definitions up to date. Viruses are small programs that can be contained in any type of executable file that you download or recieve as a e mail attachment. If you receive an e-mail attachment that your anti-virus software flags, delete or quarantine it immediately. It is a good idea to play it safe with attachments in general and not open any that aren't from a trusted source. If you receive an e-mail message with an attachment containing a virus you will not infect your system as long as you do not open the attachment.
Virus Protection Sites
Symantec McAfee
Anti Virus Xpert AntiVir Personal Edition
ILoveYouCleaner DiamondCS IRClean
VCatch Version 3.5 InoculateIT Personal Edition
Related Sites
Protecting your computers from viruses
Free Online Scanning
New virus hoaxes and false alerts
Learn about computer virus myths, hoaxes, urban legends, hysteria...