The correct answer is to Perform a scan for adware and potentially unwanted programs (PUPs). The described symptoms suggest that the computer may be infected with adware or PUPs, which are known to cause browser redirects, pop-up ads, and the installation of unwanted software. A comprehensive scan using an anti-malware tool that specifically targets adware and PUPs can identify and remove these malicious programs.

Updating the browser does not address the core problem of adware and PUPs, although keeping software updated is an essential security practice. While disabling browser extensions is a valid troubleshooting step, in this scenario, where several unfamiliar programs exist, the issue likely extends beyond just the browser itself.