很多免費防毒(直接連結)

AVG Free- antivirus(英語)
Avast Home Free- antivirus(多語言)
AntiVir PersonalEdition- antivirus(英語)
BitDefender Free- antivirus
ClamWin- antivirus
Comodo- antivirus
CyberDifender- Internet Security Suite
Ad-aware- anti-spyware
Spybot: Search & Destroy- anti-spyware(多語言)
Windows Defender- anti-spyware
SpywareBlaster- anti-spyware
Spyware Terminator- anti-spyware
Tootkit Reveaker- rootkit detection utility
Winpooch- system protection
HiJack Free- system protection
HighJackThis- hijackers detector and remover
Kerio Personal Firewall- firewall
Sygate Personal Firewall- firewall
ZoneAlarm- firewall
AxCrypt- file encryption
Simple File Shredder- securely delete files
PuTTy- SSH client
KeePass- password manager
LockNote- password manager
nPassword- password manager
MS Baseline Security Analyzer- identifysecuritymisconfigurations