i do all the time but i run linux so its funny... as for FREE antivirus, Avira is the BEST out there. malware bytes is lame and sucks and avira has way better detection rates while not bloating system resources
Yes, I have testing AV products and just for the hell of it. Once I hooked up a system with a fresh install of Win XP directly to my cable modem, no router, no firewalls, no AV software, and started browsing the internet and just clicking on shit. Within 30 minutes system started showing major signs of infection, within 90 minutes it was unusable and had about 2 dozen various trojans, malware and virii. Systems get hammered constantly, but if you have a decent router in place with good firewall capabilities, you most likely never notice. Business networks get hammered even harder. A friend who has a couple dozen networks he administers said each business averages about 1000+ hacking attempts a day, the record being over 10,000 unique attempts in less than 24 hours. I say unique because each "attack" is often a dictionary log-in attack where a script will attempt to login with various password/usernames and those can easily do 1000's such log in try's in a couple of minutes.
Use rkill.exe (download off quick google search) that will stop ANY virus that is currently infecting your system. After that you can run Malwarebytes, that's the usual virus removal procedure for regular viruses. Be careful though, there have been lucrative viruses that literally eat your computer up in hours. Usually ending up in a complete system dump and restore.
I once got a virus It's name was Cyrus It diddled my data awayyy I then took a look For the data it took And decided to read a good book for the rest of the dayyy Burma Shave