From a quite long time I was having a PlusNetwork.com search enabled in my Firefox. Whenever I used to search anything in address bar, automatically it was searched by plus network. After searching many forum's and website, got only solution to uninstall Firefox. Luckily I thought to give a try to about:config command of Firefox through which we can edit setting of FF, which help me to solve permanently PlusNetwork.com from my Firefox search. Subscribe to Syconet World by Email.
Steps to Permanent Remove PlusNetwork from Firefox
1.Open your Firefox browser and type about:config in address bar, which will show below screen. Click on I'll be Careful, I Promise.
2.Now just search for PlusNetwork and it will give you the string where PlusNetwork.com is added. It is added in keyword.URL.
3.Now just replace that URL with your own Search engine URL or simply reset it.
This will solve your PlusNetwork search problem permanently. If you have any question, then you can ask through your comments.