Do what The_Prophecy has said. run wsreset in cmd(admin).
After that, in search charm type Credential, and open Credential manager. Clear all the Credentials under web and windows.
And the most important point is, Do you use any proxy server software like proxyfire?
If yes, uninstall the software.Actually , the settings made by such proxyserver softwares bolck the store to connect.
Even I had the same problem, now its working.