Overall, in RC, Vista seems a little zippier when it connects to XP PCs. Copying files between PCs seems faster, and the time estimates that Vista gives for how long that copying will take seem to be more accurate.
Microsoft claims there have been other, minor changes as well, including a reduction in the size of standalone installers. It says that the RC standalone installer packages with 36 languages are 50% smaller than the previous beta, and the standalone installer packages with five languages are 30% smaller. In addition, the company says, disk space required for installation has decreased, and in RC, if SP1 discovers there's not enough space to install, it will tell you how much extra space you need. Microsoft also claims that the installation is more reliable, with a higher percentage of successful installs. Same changes for Windows Vista
Otherwise, the RC version of SP1 offers the same changes to Vista that the previous beta did. One of the biggest changes is in the way search works: For example, you can now use a third-party search technology, such as Google Desktop Search, as your default search engine, by choosing Start --> Default Programs --> Set your default programs. You'll see a screen that allows you to change which search tool to use by default.
In addition, if you choose Start --> Default Programs --> Associate a file type or protocol with a specific program, you'll see a new entry in the protocol section, called Search. It lets you configure which program opens when you click on a file that uses the Windows Search protocol.
In SP1, you can change your default search engine.
In addition, the Search link has been removed from the Start menu, and when you enter a search in the Start menu search box and results appear, the names of the links to additional searches have changed from "See all results" to "Search Everywhere."
If you want more information, Microsoft offers an overview of Windows Vista SP1 desktop search changes in its Knowledge Base.
There are a variety of other small changes to Vista that still appear in the RC version, including to the Disk Defragmenter, which now lets you choose with volumes to defragment, and to BitLocker, which lets you choose which drives to encrypt.
Where Vista goes from here
Microsoft is about to ramp up the beta program for RC SP1. It is now available for subscribers to TechNet and MDSN, and, it will be freely available for anyone via Microsoft's Download Center the week of December 10, 2007. Microsoft is still targeting the final release of Vista SP1 for the first quarter of 2008.