Back in mid-July 2007, Microsoft introduced the first pre-beta testing build for Windows Vista Service Pack 1. The service pack went through a series of tests and the first public release was made available in December of the past year. Since the Release Candidate for Vista SP1, Microsoft moved to the first Refresh in early January 2008. Initially a private build, dropped only to the 15,000 participants in the testing of Vista SP1, Windows Server 2008 and Windows XP SP3, Vista SP1 RC Refresh was subsequently opened up to all Vista users.

In the past week, Microsoft introduced Windows Vista SP1 RC Refresh 2, alongside Windows XP SP3 RC Refresh 2. The latest releases of Vista SP1 and XP SP3 have officially been confirmed by Microsoft, but the Redmond company failed to mention anything about public availability. As of yet, both Windows XP Service Pack 3 RC Refresh 2 Build 3282 and Windows Vista SP1 RC Refresh 2 6001.18000 are up for grabs exclusively via Microsoft Connect.

Vista SP1 RC Refresh 2 RC Build 6001.18000 is not available only as a standalone installer and an ISO download through Microsoft Connect, but has also been released through Windows Update. The problem is of course that a registry tweak has to be in place, in order for a copy of Vista to correctly identify, access, download and install the latest version of Vista SP1.

Microsoft is providing beta testers with a script that needs to be downloaded to Vista machines and then run with elevated privileges, in order to apply some modifications to the registry. "The script sets a registry key on your system. The registry key is required for WU server to recognize your machine as a valid target for Vista SP1," Microsoft informed.

According to My Digital Life, the script is widely available to the public outside of the selected pool of Microsoft beta testers. Vista SP1 RC Refresh 2 6001.18000 can be installed on top of the previous testing milestone of Vista SP1, namely refresh 1. Users also have to deploy the prerequisite updates KB938371, KB935509 (Ultimate and Enterprise editions only), and then KB937287. In the end, you will be permitted access to Windows Vista Service Pack 1 (KB936330).