Windows Vista SP1 Test Available For Public DownloadWindows Vista SP1 Test Available For Public Download

Microsoft made the first public test version of Windows Vista SP1 available for download late last Thursday, bringing the company closer to releasing the first major update to its new operating system.

The test version, which Microsoft refers to as an RC Refresh, was first made available to 15,000 beta testers last Wednesday, including corporate customers, consumers, and vendors. The release reverses Microsoft's initial stance that the version would not be publicly available.

It's not clear exactly what changed Microsoft's stance so quickly, but the release is now available.

"In the interest of gaining additional tester feedback, we made the Windows Vista SP1 RC Refresh available via Windows Update to interested beta testers on the public TechNet site," the company said in a statement.

Vista SP1 is on schedule to be released in the first quarter of 2008, though Microsoft still declines to set a final release date as it "continues to track customer and partner feedback in the beta program."

Before the public gets to downloading, people will need to make sure their computers are ready and will want to know a few things about the release. Several hot fixes need to be installed before SP1 can be, including KB935509, KB938371, and KB937287. This version of Vista SP1 is also "time-limited," meaning it won't work after June 30. And Microsoft isn't offering any assisted support; those wanting help will have to use the Windows Vista SP1 forum at Microsoft.com.

As it stands now, SP1 contains a number of features designed to enhance Vista's performance and stability. Among other things, the software offers a patch that will allow users to run the BitLocker encryption tool on multiple hard drives. It also improves the speed at which the OS wakes up from "hibernate" mode.

SP1 will also remove from Vista the so-called Kill Switch, a feature that deactivated key components of the software if Microsoft detected users were not running a properly licensed copy.