Eset Smart Security or Kaspersky Internet Security 2010 works well with Windows 7 and are recommended by many geeks here. Both contains firewall also... Otherwise, Vipre Anti Virus also gives solid protection but falsely detects some things as trojan. G Data is the # 1 anti virus engine in any of the malware tests out there. So i guess your search ends with G Data Anti Virus 2010. It has 2 anti virus engines and also it doesnt slow down your system. However, i would recommend you to 1st try any antivirus for atleast 30 days for free. Then go for the best.