You can try a good antivirus like McAfee activate who provides you with total protection along with real-time, custom scanning. It has a huge range of products for your all kinds of protection from viruses, spam filtering, infected websites, Trojan horse, and other new online threats that keep on prevailing every now and then.
Note- You needs to visit McAfee.com/activate site for installing and activating any of your McAfee products.
It is recommended before trying for any antivirus for your system, why can’t you try some simple, common precautions to exposure and protects your system, eventually-

  1. Don’t open any email attachments when send by any unknown or suspicious person
    If you don’t know the sender then don’t open, download, or execute any files or email attachments. Better delete them for your safety precautions.
  2. Don’t open email attachments even it seems it came from your known person or friend
    You must be aware that some viruses replicate themselves and spread viruses through emails (spam emails). It always better to stay in the safe side and confirm that the attachments send from the trusted source before you open it.