How do I delete the searchnu highjack virus?

I guess I accidently doenloaded the iVivid software. I have deleted it and anything connected with it by uninstalling in the control panel/programs. No matter what I do, my default browser is always returns to searchnu.com.

I have other problems--webpages won't load. I get an error that "webpages are not responding".

I guess I am infected in the registry (??). How can I get rid of this pesky thing. Or do I have to restore my factory image?

Please advise. Thank you.