This is a test of commonsense. Complete the next sentence:

How to get free virus protection software
Find out which version of windows you are running.
In general, most free anti-virus programs are intended for use with windows operating systems; however, new versions are updated for the latest windows versions.
For example, if you are still running windows xp, make sure you do not download a version only intended for windows 8 and higher.
Read the reviews carefully before downloading. Tech websites go into detail about how to avoid paying for upgrades that you don't want and other common pitfalls.