Problem to connect to Safari and App Store with Wifi after installing OS X Mavericks

I had similar problem. I upgraded from Snow Leopard to Mevrics five das ago and after that my Apple App store, Safari and Itune App Store stopped working. For your information, I use Entourage for my e mails and Entourage also was freezing. I use Mac Book Pro which I purchased in Late 2010. 2.66 ghz Intel core Duo, 4 GB Ram and 319 GB hard drive.

I tried reinstall of Mevericks 3 times, From Disk Utility I repaired hard drive and also Repared Disk Permissions 3 times, rebooted computer 3 times. None of this worked.

SOLUTION: Finaly I unchecked all of the checkmarks in the "PROXIS" screen of the Advanced section of the Network preferences and IT WORKED.

Now my Mac Book Pro and upgraded OSX Mevrickis are working fine. The Safari is Working fine and also the Itunes App Store and Apple App store can be logged in without any problems.

I hope this helps to you.

Did the same, but still have problems with Safari and Apple Store. Is it possible to solve it somehow, or just go back?