A user's laptop has been performing slowly and redirecting to unfamiliar websites. The user has also noticed random pop-up windows. Which of the following is the first step a technician should take to

The described symptoms-slow performance, website redirections, and random pop-ups-are strong indicators of a malware, adware, or potentially ransomware infection, making scanning for and identifying the malicious software the immediate and most crucial first step.

Performing a system restore is a remediation step that should typically follow an initial scan and malware identification, as an infected system restore point might reintroduce the malware.

While high network utilization can be a symptom of malware, checking it is a diagnostic step, not the primary action to address the root cause, which in this case points strongly to malware.

Updating antivirus software is an important preparatory step, but the first active measure in this scenario is to initiate a scan to detect and potentially remove the already present infection.