If you want antivirus software to not slow you down, these are the programs to buy (or avoid). Antivirus programs can slow your computer, sometimes by quite a lot. … Which antivirus software has the least system impact? Bitdefender Total SecurityPassive slowdown19.2%Full-scan slowdown32.7%Quick-scan slowdown30.1%Which Antivirus Software Has the Least System Impact? | Tom’s Guide www.tomsguide.com › av-software-least-system-impact,review-6276