I have recently purchased a new HP 500 – 590 running windows 7 Pro with 8 gigs of RAM. I have McAfee livesafe antivirus and I believe Windows defender is also running. The computer and programs have all the latest updates. If I'm at my desk working on the computer for 3 or 4 hours or so my Internet browsers will stop accessing the Internet. I will have various programs open such as Pandora and Dragon NaturallySpeaking as well as IE 11 and Chrome and other third-party software that I use for by job. At some point the Internet browsers will stop accessing the internet and whatever websites they are currently on. I have shut down McAfee, rebooted my cable router, and closed whatever other programs will be currently running but still cannot access the Internet with the browsers. I know the computer still has access the Internet as Pandora can still play and the Internet icon on the taskbar is clear. The only fix I've been able to come up with is to reboot the computer. Does anyone have any other ideas on what could be blocking browsers access? Thank you.