Try uninstalling and reinstalling the browser.

Yes Did that many times bro. But sometime problem resolved for few days and comes again.

When I open opera browser, Come this error. I got a screenshot of the error. take a look here. http://i.imgur.com/CTYPZfs.png I can not go any web site or open any tab. If open a tab, the same error comes up. What is the solution for this?

@blackbird71 thank you for the help. I'll try in that way.

Istartsurf is adware and a PuP (potentially unwanted program) that comes bundled with freeware downloads. Usually, it's best to simply start with @gwen-dragon's third suggestion: Malwarebytes and AdwCleaner. I've yet to personally run into an infection from this class of adware that responded to "ordinary" removal efforts via add/remove programs and so on. The last one I helped a user with had covertly created 19 slightly different variations of itself on the system. While manually removing it via add/remove took out the original entry, it was auto-replaced an hour later by another variation of the same thing. The PuP had infected the start folder, the registry, the task scheduler, the browsers, and a number of file folders so it could resurrect itself periodically from a variety of scattered implants. Malwarebytes did the trick on that beast, but it's always wise to get a second "clean" opinion from another reputable tool. Be VERY careful about downloading an off-brand specialized removal tool if you don't know the reputation of its maker - some outfits use pretend-removal tools to infect a system with something worse than what is being targeted for removal.

Hey I did it in Malwarebytes. But it's already there.

Hi there! There is a search bar installed of my opera browser that called istartsurf.com how can I remove it. I tried to remove it in many ways. But I couldn't please halp me. Thanks