Although Microsoft has failed to confirm the date when the code for Windows Vista Service Pack 1 will go gold, all indications point to mid-February 2008 for the releasing to manufacturing of the refresh. Following the RTM of Vista SP1, it will be served as an update through Microsoft Update. In this regard, Dustin Jones, Program Manager on the Microsoft System Center Essentials team, informed that Windows Server 2003 users would experience problems in accessing Vista SP1 via Windows Server Update Services. The reason for this is the fact that WSUS is unable to deliver large Windows update files in Windows Server 2003.

"The patch is very large and there is a bug in Windows Server 2003 in the WinVerifyTrust API that will cause signing validation to fail," Jones explained. "What this means is that once you approve this update on a System Center Essentials 2007 server on a Windows Server 2003 server, every time the server sync's from MU it will redownload the package, fail the cert validation, and so the download will fail. The problem will continue until you install the WinVerifyTrust patch on the System Center Essentials server. This patch is a hotfix (not a public GDR), so is not intended to be widely distributed. We recommend it only be installed on the System Center Essentials server itself."

KB article 888303 and the associated hotfix have been up since 2007, but the source does not specifically mention Vista SP1. However, it is designed to deal with the download failures of large Windows updates via WSUS on Windows Server 2003. Essentially, the problem is connected with updates that are over 700 MB in size. In such scenarios, the download will fail.

"A supported hotfix is now available from Microsoft. However, this hotfix is intended to correct only the problem that is described in KB888303. Apply this hotfix only to systems that are experiencing this specific problem. This hotfix might receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next service pack that contains this hotfix," Microsoft added.