Comodo Internet security is one of the best free, if not Best Free Internet security suit out there.
Its did good but not 100% Perfect which is impossible.... first let me grade it:
Signature Based Malware Detection and Prevention: VG
Zero-Day protection G
Memory-CPU useage G
If its easy to use and its interface is not messy. G if a bit Tech savy - O for Begginers
Easy install-Uninstall G
Scanning and Update speed G
Comodo did amazing, It missed only 2 files out of the 20 tested.
VG - Very good - Highest grade it can get
G - Good - Second Highest
O - Okay - Middle
P - Poor - Second Lowest
VP - Very Poor - Lowest
Read it here on my Blog: