[5aces]

Other secondary products I have used:

http://www.zemana.com/ Free and paid versions of Keystroke Encryption programs.Nice.

http://www.surfright.nl/en/home/ HitmanPro 3,installs onto a USB key and Kickstart module foils malware that holds your computer for ransom.

Press Ctrl on keyboard while starting the program and it will stop any process that prevent installation of security programs.
The feature known as Kickstart has worked for myself a couple times on infected PC's.
Similar alternative to Malwarebytes.

 

[pooley]

Also use MSE and Malwarebytes + common sense, don't go browsing dodgy pron sites lol

 

[Currawong]

Firefox with NoScript. A dodgy web page can't hijack your computer if scripts can't run. Makes browsing a bit of a PITA, as you have to manually enable scripting for sites, but will pretty much stop zero-day attacks too.

 

[kymira]

I was going tor recomend Kaspersky but it already seems you've already tried it. Like others have said try MSE first, you cant go wrong its free.

 

[Tiemen]

Comodo for the win.....

 

[cme]

I use Microsoft Security Essentials and it's fine. It's free, reasonably effective, reasonably efficient (lower impact on performance), updates in the background and never prompts me to buy more features that I don't need.
 
I do also run a firewall and flash/script blocking add-ons for Firefox and generally use common sense.
 
It's still possible to get infected (all scanners lag by days; all scanners leave some exploits open).

 

[peterdavidson99]

AVG and Immunet are the best. 

 

[Tiemen]

I like this one:
http://360safe.com/totalsecurity.html