There are several ways of practicing safe computing. The absolute first rule should be for you to ensure that there is virus detection software running on your computer. The second rule should be that you should ensure that the virus definition files are current. These virus definition files may be downloaded from most virus detection software companies. The definition files are updated as new viruses are discovered.
Also, should be to never trust the integrity of the data on any disk or program file that you are given. Always check the files on a floppy diskette that someone has given you with a virus detector. And never trust any files that you have downloaded off of the Internet without first running them through a virus detection program.
Lastly, never take it for granted that your files are clear of viruses. Most virus detection software has the ability to do a thorough scan of your local disks at a predetermined time. This means that you can perform a complete virus scan on your computer in the evening while you are sleeping.