Kaspersky employed a unique dual-engine approach:

Unlike today’s all-in-one "Internet Security" suites, the 2014 Free edition had a very specific job: It did not include a firewall, parental controls, or a password manager. This made it incredibly fast.

Software built in 2014 is designed for Windows 7 or Windows 8. It will cause severe stability issues, crashes, or system failure on modern operating systems like Windows 10 and Windows 11.