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When creating an Update List and downloading software updates for Visual Studio 2005 and 2008, some but not all of them may fail with the error "invalid certificate signature" in the confirmation page of the Software Updates Deployment Wizard. This is seen with System Center Configuration Manager 2007 and can happen for other large updates as well. The hotfix from http://support.microsoft.com/kb/938759 does not help in these cases.
Cause: This is a known issue with the Configuration Manager Console running on Operating System prior to Windows Vista, such as Windows XP and Windows Server 2003. This is documented here:
http://technet.microsoft.com/en-us/library/bb932193.aspx under the heading "Downloading Large Software Update Files Might Fail"
Resolution: The workaround for now is to use Windows Vista, Windows Server 2008 or Windows 7 to run the Configuration Manager Console to download these larger updates.
Clifton Hughes | Senior Support Engineer
I've encountered this error when attempting to download some updates on a console running on Windows Server 2008 R2. For some of them I was able to get them to download by disabling Protected Mode for the Internet zone, but others still have the problem. I haven't been able to identify a secondary solution.
I found that if I closed and re-opened the Configuration Manager Console after disabling Protected Mode the problem updates would then download.