PrevX is a well-known security vendor. If you like the software, GeorgeB, then by all means go for it. Just remember that it takes more than an antivirus software to keep your computer secure. In addition to Microsoft Security Updates and a software firewall, updates to third-part software are also needed (i.e., Adobe and Oracle SunJava). It is generally recommended that at least one anti-malware software program be included in our security arsenal. Consider Windows Defender, Malwarebytes' Anti-Malware or SuperAntispyware.
Let us know what you think of PrevX3.