Computer won't connect to the internet?

Ok, so I have a desktop that has windows 7 Professional and no Wi-Fi wireless card, so I have to use an ethernet cable. About 2 weeks ago I turned on ready to do stuff on the internet, but it wouldn't do anything. It said it was connected to the internet and working, even the troubleshooter said it was perfect. I use Opera and Google Chrome and they both said I was having network problems, like the internet was off, even though it's working fin on my laptop and iPhone. I decided to look around the web and found a lot of fixes, all to no avail. I did find one though that said the firewall could be the problem, I went there and tried to open it and go through the settings but i get the error code "0x80070424".Is there any fixes other than restoring my computer to factory settings? I'd rather not do that as I have a lot of work I would like to save.

Have you try to used system restore, it is one of windows feature that enable you to roll back to the time where your windows is running well, to open it just have to click start and type system restore then enter, after that click next and then choose the time where your laptop ethernet is still in good condition.