Windows 7 Upgrade Advisor tool failed to run with error message “Windows 7 Upgrade Advisor was unable to reach the Microsoft server for compatibility information. Check your internet connection and try again later.”


Symptoms


When you run the Windows 7 Upgrade Advisor tool on a system that must use a proxy in order to access the internet you receive the error:

 
“Windows 7 Upgrade Advisor was unable to reach the Microsoft server for compatibility information.  Check your internet connection and try again later.”

Cause


Windows 7 Upgrade Advisor tries to reach the Microsoft server to get the compatibility information. The error is shown since Windows 7 Upgrade Advisor does not support proxy authentication.

In the error log (%temp%\WuaDiagnostics.log) you can see the update advisor tries to access:

http://aeos.microsoft.com/compatibilityexchange/compatibilityexchange.svc and then receives the error like following:

[7/23/2010 12:04:41 PM] Exception: The request failed with HTTP status 407: Proxy Authentication Required

Resolution


On the proxy, create an anonymous access rule specific to the destinations FQDN's used by the Windows 7 Upgrade Advisor, for example, you may create the following rules:

Action: Allow
Protocols: HTTP, HTTPS
From/Listener: Internal
To: Domain Name Set
aeos.microsoft.com
aestats.microsoft.com
crl.microsoft.com
download.microsoft.com
go.microsoft.com

Condition: All Users