If its a toolbar.. see link below
If its the search page, you have to change your default search page setting in the browswer.

What browser do you use ?

Here is a link that might be useful: http://www.toolbarremover.com/ freeware

Here's instructions on setting default search for google...

Here is a link that might be useful: support.google....

that does come as an addon so go into the area where you have addons listed and try removing it from there. I don't use chrome, but in firefox it is under tools>addons.

Do you know when you installed it if it was recent your best bet with this stubborn thing might be to do a simple system restore to the day before you installed it.

any time you ask for help please tell us which version of windows you are using and the versions of the browsers since those will require different instructions.

If you need instructions for doing a system restore we need to know your windows version.

I would also run an updated malwarebytes free scan because that thing is often associated with malware.
Malwarebytes' Anti-Malware (Win) - Detecting and Removing Malware
and superantispyware
SUPERAntiSpyware.

as I said this thing is notorious for linking with known malware, this is one statement I found
"We found that the software has certain suspicious behavior such as downloading malicious codes, installing toolbar with users� acknowledgement as well as changing homepage."

Running malwarebytes and superantispyware should take care of it but if not let us know.