Tools

Set a System Restore Point before attempting any system repairs. (Start - Programs - Accessories - System Tools - System Restore)

Anti-Virus

AVG Free Anti-Virus and Anti-Spyware
(Windows 2000, XP, XP64, Vista, Vista 64)
avast! Home Edition
(Windows 95, 98, Me, NT4.0, 2000, XP, XP64, Vista) Avira AntiVir Personal - Antivirus
(Windows 95, 98, Me, NT4.0, 2000, XP, XP64, Vista)

Firewalls

Zone Alarm Basic Firewall
(Windows 2000, XP, XP64, Vista, Vista 64)
Sygate Personal Firewall
(Windows 98, Me, NT4.0, 2000, XP, XP64, Vista)

Cleaners

CCleaner
(Windows 95, 98, Me, NT4.0, 2000, XP, XP64, Vista)
CounterSpy (15 day free trial)
(Windows 95, 98, Me, NT4.0, 2000, XP, XP64, Vista)
The Cleaner
(Windows 2000(sp4), XP(sp2), Vista)
HiJack This
HJT Help

General Resources

Geeks To Go - Things to do if infected
Tech Support Guy - Security Help Tools

Browsers/Email

Opera
Firefox
Maxthon
Thunderbird Mail

Links

Financial

Travel