Parallels

Symptoms

Windows updates are not downloaded and the following warnings might appear in %windir%\WindowsUpdate.log file on the server:

WARNING: WinHttp: WinHttpQueryHeaders(WINHTTP_QUERY_CONTENT_LENGTH) failed. error 0x80072f76
WARNING: GetServerFileSize failed. error 0x80072f76
WARNING: WinHttp: IsFileToBeDownloaded failed with 0x80072f76
WARNING: WinHttp: ShouldFileBeDownloaded failed with 0x80072f76

Cause

The problem can be caused by the following reasons:
1. An internal firewall prohibits connections to Parallels WSUS server;
2. Hardware Node is located behind an internal proxy server;
3. WSUS settings are changed on the server and point to a different WSUS server than Parallels WSUS server.

Resolution

Micorsoft recommends to use WSUS Client Diagnostic Tool (readme) in troubleshooting the communication between the WSUS Server and the client machine.

The recommendations listed below provide general guidelines how to troubleshoot the issue:

1. An internal firewall prohibits connections to Parallels WSUS server:

To avoid the problem it is necessary to make sure that vzwinupdate.sw-soft.com server is reachable from Hardware Node by 80 port.

2. Hardware Node is located behind an internal proxy server:

Firstly it is necessary to verify that Hardware Node is configured to use correct IP address of the proxy server.
The "proxycfg.exe" command shows and configures proxy settings on Windows servers.
Some proxy servers implement a logon requirement. If the proxy server requires authorization by user name to gain access to Internet such Hardware Node cannot be configured by using "proxycfg.exe" tool.
In this case you should use some firewall/proxy client application which authorizes the user on the proxy server. For example Firewall Client Tool shipped with ISA Server 2006.

3. WSUS settings are changed on the server and point to a different WSUS server than Parallels WSUS server.

The following command displays WSUS settings of a server:

Reg query "HKLM\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate" /s

There are two important keys shown below and its values that point from which WSUS server windows updates are downloaded:

"WUServer"="http://vzwinupdate.sw-soft.com"
"WUStatusServer"="http://vzwinupdate.sw-soft.com"

The problem usually occurs if Hardware Node is member of Active Directory domain and default group policy is applied.