Case Study: Desktop IE works but Modern UI IE fails to connect to the Internet on Windows 8

 

Symptoms

A customer reported that he failed to connect to the Internet in Modern UI IE on this Windows 8 however he can use the Desktop IE on the same machine.

Modern UI IE has already been launched. Two iexplore.exe processes (Frame process and Tab process) appear in Task Manager. We type URL in the address bar and then press ENTER. However there is no response.

 

Troubleshooting

We captured the Network Monitor trace and found no HTTP request was sent out. Before we planned to do the debugging, we decided to capture Process Monitor logs.

 

In the logs we noticed that iexplore.exe failed to open the registry key HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\SideBySide due to “Access Denied”.

 

We checked the permission on SideBySide registry keys and compare it with other machine. On a normal machine “ALL APPLICATION PACKAGES” has Read permission on HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion (The permission on SideBySide key inherits from the parent folder). But on that problematic machine this permission is missing.

 

If we add back this permission, the problem disappears.

The root cause is that the customer’s group policy removes this permission.

 

Conclusion

1. The Modern UI IE (like other Windows APP) runs with very limited user rights compared to their non-Windows 8 counterparts that run with standard user rights by default. It can access only those resources (files, folders, registry keys etc) to which it has been explicitly granted access (“ALL APPLICATION PACKAGES”).

https://technet.microsoft.com/en-us/library/hh832040.aspx

https://support.microsoft.com/kb/2798317

 

2. Process Monitor is very useful for troubleshooting IE problem. Pay attention to the trivial errors. (e.g. “Access Denied”)

 

Regards,

 

XinJin from APGC DSI Team