Windows Vista SP1 RC requires the installation of either two or three prerequisite updates prior to installing the service pack itself. Also prepare for several reboots before you actually install the SP1 RC update. This entire process could take from 30 minutes to 1 hour depending on your hardware. Instructions and 2 methods of installation are outlined on the Microsoft support site.
Microsoft has also released a detailed roster of the contents of its forthcoming service pack for Windows Vista, and the list includes more than 300 hot fixes covering everything from data protection to video performance.
The list, recently posted on Microsoft's Web site, can be downloaded as a 47-page document that the company says is not exhaustive. Microsoft plans to add more fixes and patches to Windows Vista SP1 before a final version is released to the public early next year.