Germany's thickest men's magazine c't presented recently fixed again as full of holes is the Windows-virus protection at the factory. Not even any external solution found with regard to the detection of unwanted intruders grace the tester. F-Secure was definitely the most reliable solutions. It monitors if desired the Browser and warns of phishing and drive-by attacks. A dedicated firewall missing, but there are then but with Windows.
The program integrates unobtrusively into the computer. A noticeable slowdown or start delay I could not tell. Additional devices can be added easily.