On January 9, 2008, Microsoft made available Windows Vista SP1 Release Candidate (RC) Refresh - Build 17128. This is the latest development milestone release of Vista SP1, following the first publicly available build of the service pack, served in December 2007. In the past month, the Redmond company opened up the testing process of Vista SP1 to all users of the operating system, by offering the first Release Candidate of the service pack. However, with the January 9 release, Vista SP1 went back to private testing.

Vista SP1 RC Build 17128 was dropped into the laps of approximately 15,000 testers via Microsoft Connect. The company informed that only the select group of testers 15,000, strong including "corporate customers, consumer enthusiasts, software and hardware vendors", had been permitted access to the code, and that the bits will not be made available to the rest of the Vista users. The fact of the matter is that Vista SP1 is in the final stages of development with the RTM as close as February 2008. In this context, with so little time before the code goes gold, you might try and exercise your patience and wait for the final release.

On the other hand, Windows Vista SP1 is not only available for download on Connect, but also as update via Windows Update. The current configurations of Windows Vista, however, will not detect the update. This is why Microsoft delivered a script designed to set a registry value that will make the Vista SP1 RC Build 17128 visible to all copies of Vista. The WU redirection script was leaked to the web, and is available for download here.

The hack will set a registry value that will enable you to access, download and install Build 17128. The private Vista SP1 RC Refresh is 6001.17128.080101-1935 v.774 and it is designed to replace the public RC Vista Build 6001: Service Pack 1, v.668. But be advised that you will have to uninstall the previous version of the service pack, in order to deploy the refresh. At the same time, you will also need the Vista SP1 prerequisites KB935509 (for the Vista Ultimate and Enterprise SKUs), as well as KB938371 and KB937287 for all Vista editions.