iPhone / iTunes Software Update Server Could Not Be Connected

iPhone / iTunes Software Update Server Could Not Be Connected

1. I can't go into iTunes Store

2. I can't update iPhone and iTunes

3. I can't download what I purchased before

What I did (My internet connection is great)

1. CMD -"netsh winsock reset"

2. LAN option change

3. Uninstall and Re-Install several times

All I did didn't work at all.

What's the problem with my PC and iTunes?