I actually used free AVG for quite some time and actually managed to install the stuff without the dreaded toolbar.
But got annoyed when it was always checking every file I wanted to open, even applications I had written myself, so uninstalled the stuff.
For more years than I can remember I have used Win 7 with no AV software.
Only time I got caught out was when a (presumably) virus software dropped its installation file into a WinSys folder and tried to install itself every time I booted up
User Account Control would cut in, as it should and gave me the expected option, which was obviously "Refuse". So then it would do it again, so I used task manager to stop it.
Located the file in, I think it was System32, but it would not delete.
So choices, either stick a bootable CD in the tray and get into the file system there, or take the HDD off and put it in a second machine as a slave and delete the virus file that way.
Had a good old rummage but could not find a disk, so went the other route. Took all of 20 minutes.
Only time in years had this happen, and I mean years.
Another thing while I am on, and lamp customers on here will have noticed this.
All emails in and out are converted to plain text on my system, so who needs graphic headers and nodding dogs anyway.
Its good security.
Emails to plain text, only download essentials such as Adobe Reader from the official website, dont download anything else (EasyDocMerge and this kind of crap) and if Windows tells you anndnbsyg or whatever wants to make changes to your computer, pull the bloody plug out the wall if you have to
Sorry I forgot. Email attachments, dot zip, dot kak, dot scr, no no, I only open ones from someone I know which are of a harmless file type.
But even then you would have to give Windows permission for it to install.