MIcrosoft security essential is best and its free 

AVG Antivirus Free Edition 2012.
 

For more list click here.

use avira.it is a free version and effective av... 

Kaspersky PURE.... All in one protection but its price is Rs. 1995 (1PC-1Year). Microsoft Security Essential is free and easy to use.

Avast Home Free Version with a combination of Malwarebytes Anti-Malware Free version. These both will not clash and will give you fine protection. 

gO FOR KASPERSKY

Try to migrate to Linux or Unix, you will find no virus,

Originally posted by : Rahul Sharma
	MIcrosoft security essential is best and its free

i think rahul has point

i hv used all the above listed antvrs

most effective is MS Security Essentials no doubt

try all .....u will definitly suggest same

Originally posted by : Rahul Sharma
	MIcrosoft security essential is best and its free

best among the free ones..use original os..
 

Originally posted by : MANU
	Originally posted by : Rahul Sharma MIcrosoft security essential is best and its free    best among the free ones..use original os..

infact any microsoft product should be used in original os.