How do I keep my computer safe from viruses?

Perform Regular Virus Scans. Conducting regular virus scans of your computer systems with an updated virus scanner can drastically limit the opportunity of any virus infecting or causing serious damage to your computer.  Enable your Windows Firewall.

Here are some free (for personal use) Anti Virus programs:

Windows 10 has a free built in firewall and anti-virus (Windows Defender).  Keep this enabled and active.