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."

This article provides a solution to an error that occurs when you run the Windows 7 Upgrade Advisor tool on a system.

Applies to:   Windows 7 Service Pack 1
Original KB number:   2448270

Symptoms

When you run the Windows 7 Upgrade Advisor tool on a system that must use a proxy 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 doesn't support proxy authentication.

In the error log (%temp%\WuaDiagnostics.log), you receive the error like following one:

[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 (fully qualified domain name)'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

Data collection

If you need assistance from Microsoft support, we recommend you collect the information by following the steps mentioned in Gather information by using TSS for deployment-related issues.