MacBook Air problems

So my techy friends, I seem to be having an issue with my laptop. I know that we all usually discuss here any website related issues, but since I know a majority of people here might be running Apple OS, I though that I would give it a shot to see if anyone here can help me with my issues before I look else where.

So I have a 2011 MacBook Air, and my housemates son was downloading modes for his PS3 games on it, but deleted them after he saved them to his USB.

Ever since, I've been getting pops like crazy, or click on something and a new window pops up for an ad and I have to X out of it right away. It's been super annoying to say the least.

Now tonight, I'm on the WA website, and I cannot post comments (they just disappear once I press the "reply to comment" button. I cannot even get to my profile when I try to click on it. And several other site related issues.

I've looked at my Safari settings, and it says that all of my security is correct and enabled and pop-up blockers are on.

Is there a way that I can reset it to the factory settings like you do to an iPhone, or does anyone have a simpler solution because I am ready to throw this thing through the window!!!!! OMG! lol

I also don't have any security running other than what comes on the computer (OS security).

Any suggestions would be greatly helpful!!

Thanks friends :)