When the CRN Test Center last looked at Microsoft Windows Vista, it was obvious the operating system was far from complete, which wasn't a surprise because it was still a beta version.

On Sept. 1, Microsoft began rolling out Vista Release Candidate 1 (RC1), raising hopes that all of the major issues have been resolved in the months since the beta two version. And it appears those hopes have been largely fulfilled.

RC1 brings measurable improvements to Vista and should help assuage some key concerns about the operating system, such as compatibility, performance and readiness for Microsoft's planned ship date of January 2007. RC1 also brings a stable enough version of Vista so that system builders and integrators can learn the ins and outs of the platform before gold code hits manufacturing.

Microsoft typically has put out a release candidate before shipping the gold code of a product, an indication that the feature set and user interface are pretty much complete.

Test Center engineers took a long hard look at Vista RC1 and saw some major improvements that bode well for solution providers looking to jump on the Vista bandwagon next year. That said, RC1 is far from final code, and some issues still must be resolved before Microsoft can release the final Vista product, which will probably lead to an RC2 version. Those issues include upgrade compatibility from Windows XP and final code updates for Internet Explorer, along with some other applications.

But for now, here's a look at the top five improvements that RC1 brings since the beta releases of Vista:

1. INSTALLATION
With the Vista beta, installation was a long, arduous process. In some cases, it took more than two hours to install and configure the OS. Installation also often failed on some notebook computers and some newer desktop PCs.

RC1 addresses those problems with a much-improved installation process. Installers can now boot directly from the DVD without having to worry about unexpected prompts and misidentified hardware derailing the install, or having to wonder if the installation has frozen.

Whereas installation took as much as two hours in tests of the Vista beta, RC1 reduced the installation time to less than an hour on the same equipment. In addition, several systems that refused to accept the Vista betas readily worked with RC1.

Installation problems have been resolved to the extent that system builders should have no qualms about testing Vista on their various hardware platforms and ramping up for the operating system's availability early next year.

NEXT: Drivers and performance.