The reference system without any protection software was used for later comparison of the measured performance ratings. In addition, a Windows system with the freeware Microsoft Security Essentials or Defender (for Windows 8/8.1) was put through all the tests as an additional comparative figure. Included in the test were products from Ahnlab, Avast, AVG (freeware and purchase product), Avira, Bitdefender, BullGuard, Comodo, ESET, F-Secure, G Data, Kaspersky, McAfee, Microworld, Norman, Norton, Panda, Qihoo 360, Quick Heal, Tencent, Threat Track and Trend Micro.