Struggling with pop.adv.net popup which pops up randomly

Recently some trojan has messed up my computer . What it does it very annoying . It generates pop-ups showing ads at random intervals while you are browsing. I searched google and tried out many solutions suggested by many forums but till date my system is infected.
I installed firefox addons like noscript and adblocker to prevent these sort of attacks but this is temporary solution and my system is still infected.

If anyone knows of a solution which has worked for them , please let me know as well.