Computerhilfen.com: Internet wont load about every 2 hours

About every 2 hours I have to restart my computer, (http://www.computerhilfen.com/explanation-c-Computer.html) or the internet (http://www.computerhilfen.com/explanation-i-Internet.html) won't show up. It always says its done loading but the window is blank (http://www.computerhilfen.com/explanation-b-Blank.html) white. It does that for every website. And its not just Mozilla Firefox (http://www.computerhilfen.de/download-8451109180319399.html) either, Internet (http://www.computerhilfen.com/explanation-i-Internet.html) explorer and Opera do the same thing.