One of the ways that computers are getting hacked is that people are clicking on email attachments with malware installed. If they have File Extensions turned off, which is the default, then they may not see the .js or .exe extension. A file which displays as retirementinfo.docx may actually be retirementinfo.docx.exe. which might have malware embedded. What you want to do is unclick the “Hide extensions for known file types.”
Here’s a video for Windows 7
In Windows 10 do a Search for “hide file”and it will show you the link to make the change.