In the controll pannel, start rogramms and functionalities.
Look if you find omiga-plus. If present, uninstall it from there. In some cases, you may need to do that when logged in as administrator.
Think about switching to another browser. Chrome is OK, and Firefox is another great alternative. Performance wise, they are praticaly the same.
AdBlock Plus is available on both. Absolutely great addon that makes your surfing faster by not loading many ads and make your internet experience much more enjoyable.
Think about installint the NoScript addon. Great for blocking unwanted scripts. Available for both Chrome and Firefox.
Don't wory about trackers. Their only goal it to serv you with personalised advertisement. "Disconnect" is an useless thing for the paranoyd.
I recomend having two, maybe tree, anti-virus: One set to run all the time and the other(s) to be run manualy frome time to time.
3 anti-virus suggestions:
AVG free version from free.avg.com
Avira from www.avira.com
Avast from www.avast.com
Fact: NO anti-virus can ever hope to catch and remove all infestations, ever.
To get rid of other pests, you should use Spybot Search & Destroy. Available here: http://www.safer-networking.org
Free for personal use.
It's a realy great utility to remove, and prevent infestation from, all sort of non-virus undesirable stuff.
Be sure to run the immunisation: It fools many maleware into "thinking" that they are already installed and running, or that your computer is not compatible.
To prevent future browser hyjackers and other junk in the future:
When installing ANYTHING. never ever choose the default option.
ALWAYS use the custom or personalised option.
ALWAYS decline ANY offers or recomended side installs, accessories and changes. None are needed.