i found malware bytes antimalware to be a good thing against some trojans and spywares..and it is totally free for scanning though you will have to buy for real time protection..still i must say very good..as it doesn't each up ya resources...
http://download.cnet.com/Malwarebytes-Anti-Malware/3000-8022_4-10804572.html?part=dl-10804572&subj=dl&tag=button