What antivirus are you using? Free or Paid?

I use Windows Defender, Malwarebytes Anti-Exploit(free), Spywareblaster, Winpatrol and Privacy Badger.
Sometimes changing anti-virus to Avira free.

Started off with McAfee (came pre-installed with the PC), however it bashed up my PC real bad. So uninstalled it and went for Avast (Free edition) works like a charm :)

tanujchadha said:

Started off with McAfee (came pre-installed with the PC), however it bashed up my PC real bad. So uninstalled it and went for Avast (Free edition) works like a charm :)

Hmm, I had McAfee preinstalled and the malware scan kept freezing. I can't be doing with AV that fails in any way, so it had to go. Now using Emsisoft Anti Malware paid. It also blocks hosts that are used for advertising or tracking purposes. Brilliant.:)

Bitdefender & Malware Anti-Malware.

I just use Windows Defender these days, I keep a copy of malware bytes around in case I feel I need a additional scan but have yet to run into this. Honestly I have not had any virus problems since I stopped torrenting years ago and using mass software downloads from Ninite.com. Good browsing habits + Defender+ good firewall configuration = A stable and secure system

TrustPort Antivirus 2015.

Bitdefender 2015 Maximum Security no complaints and runs smoothly than ever.

I have a general question about anti viruses:
If there are millions of known viruses in the database of some anti virus software, how can it scan so fast?
Doesn't it need to check each and every file and match it with millions of viruses? So how does it scan each file in a millisecond?

It's the heuristics that scan each and every file after folder scan. It will see if any MD5 hash is identical to the database and then flag it as malware.

I am using Windows defender now