Routinely scan your computer for malware
컴퓨터에서 주기적으로 악성코드 검사
->Literal meaning sounds awkward. Since malwares are scanned in computer, the directional verb ending won’t be appropriate in terms of sentence flow.
Uninstall unfamiliar or suspicious extensions
낯설거나 확장 프로그램 제거
->The second adjective ‘suspicious’ is missing in translation so the string doesn’t make sense at all.
Uninstall suspicious programs from your computer that you don’t remember installing.
컴퓨터에 설치한 적이 없는 의심스러운 프로그램 제거
->’don’t remember installing’ doesn’t follow the source. It reads ‘never installed’