Internet will not work on my PC.?

[Billy]

I have a custom PC with Microsoft Security Essentials for virus protection. Around 2 weeks ago when I switched on my computer it connected the internet and when I opened my browser (Opera) it told me that the Dns look up failed and that I am not connected the internet. When I open the programme steam my friends list shows up and also shows who is online but everything else on it does not work. I have tried using the internet through other browsers but is does not seem to work. I have tried everything I can from console commands to resetting. Every other device in my house that uses the internet works. The only thing I think could potentially be the problem is when I check security essentials there is lots of blocks for Adware:Win32/BetterSurf. I really need a quick solution because I need my PC to study for my upcoming final exams

[Anthony]

It sounds like the DNS service is not working, do you know how to change dns? Go to your local Area Connection Dialog box settings > Right click > click on internet protocol v4 and under use the following dns service address and use google public dns 8.8.8.8

If your internet works, it's your local ISP DNS settings that's the problem

Hope it helps

Regards
Anthony