Please help me remove 'Internet Security Essentials' virus

I am running Avast Antivirus and have been for a while now but today my husband inadvertantly downloaded ‘Internet Security Essentials’ thinking he was being infected…and now of course I’m stuck with it…and Avast didnt pick it up??

Can someone plese please help me remove it?..I have downloaded a couple of ‘tools’ but once they scan the computer they ask for money and at this stage I am hoping there is a ‘free’ one somewhere?

This is a horrible virus and is driving me crazy!

Thank you…

Is it any of these ?

Remove Security Essentials 2010 (Uninstall Guide)
http://www.bleepingcomputer.com/virus-removal/remove-security-essentials-2010

Remove the Fake Microsoft Security Essentials Alert Trojan and AntiSpySafeguard
http://www.bleepingcomputer.com/virus-removal/remove-fake-microsoft-security-essentials-alert

Remove Internet Defender 2011 (Uninstall Guide)
http://www.bleepingcomputer.com/virus-removal/remove-internet-defender#keys

Remove Personal Internet Security 2011 (Uninstall Guide)
http://www.bleepingcomputer.com/virus-removal/remove-personal-internet-security-2011

The tool used in these guide ( Malwarebytes ) is free and will remove the bugs for free
read it all before you start