One user came to see me after the recent windows updates. Her machine suddenly lost internet connection after the updates were applied. From my experience, the problem is usually caused by firewall. I turned off the ZoneAlarm firewall and internet started to work again.
ZoneLab published an article about this issue. You can visit their site to download the latest updates for ZoneAlarm, or you can follow the instructions to solve the problem.
Option 1: Move Internet Zone slider to Medium
- Navigate to the “ZoneAlarm Firewall” panel
- Click on the “Firewall” tab
- Move the “Internet Zone” slider to medium
Option 2: Uninstall the hotfix
- Click the “Start Menu”
- Click “Control Panel”, or click “Settings” then “Control Panel”
- Click on “Add or Remove Programs”
- On the top of the add/remove programs dialog box, you should see a checkbox that says “show updates”. Select this checkbox
- Scroll down until you see “Security update for Windows (KB951748)”
- Click “Remove” to uninstall the hotfix