I guess it's a big day for Windows fans: The long-awaited first public pre-release version of Windows Vista Service Pack 1 (SP1) is upon us, like an answered prayer from Redmond. At the risk of sounding like a spoilsport, however, SP1 isn't really all that exciting. As I noted in my previous SP1 missive, Inside Windows Vista Service Pack 1, it is instead very much an evolutionary update to Microsoft's latest client operating system, one that, in the words of Microsoft itself, doesn't really change the Vista value proposition.

What makes Vista a big deal, really, isn't so much what's in it as what's behind it. You see, there's this perception in the Windows world that businesses won't deploy any new Windows OS until the first service pack ships. Microsoft had hoped to avoid this problem by ensuring that Vista was the highest quality version of Windows they'd ever made, with the theory being that it was so good that no business would want to wait. Obviously, that's not what happened at all. And as I write this in the waning days of 2007, Microsoft is on track to sell about 100 million Windows Vista licenses in its first year on the market, well short of any internal or external goals.

So if you were seriously waiting for SP1, I feel for you. I will argue, as I have all along, that Vista was quite good, thank you very much, the moment it sprang out of Microsoft's womb in late November 2006. I will point out that the intervening year has seen dramatic compatibility and performance enhancements to Vista, and that the experience of upgrading or installing this new OS is now better than it's ever been. And I will bore you with tales of how uninspiring Vista's predecessor, Windows XP, is by comparison.

None of this matters. You are, of course, waiting for Windows Vista SP1. And you will be happy to hear that Microsoft will make available the first public version of this important, if non-seismic, OS upgrade as soon as next week. This version, called Release Candidate 1 (RC1), is the last major pre-release milestone version of Vista SP1 that Microsoft will issue before the final release in Q1 2008. It is nearly feature complete, missing only the WGA update that I discuss in my showcase, New WGA Behavior in Windows Vista Service Pack 1.

What I won't be discussing is the contents of the service pack. That is fully disclosed in the Inside Windows Vista SP1 article mentioned previously. Instead, I'll focus here on the installation experience and what's changed since the beta.

RC1 availability

Microsoft is delivering Windows Vista SP1 RC1 in three different formats, though only two of these will be made available to the public.

DVD

This is the so-called "full install" of Windows Vista SP1 RC1, and it's available in two different versions, a DVD for English, French, German, Japanese, and Spanish, and a second DVD for all of the 36 languages that Microsoft will ship this release in. Both DVDs include the x86 (32-bit) and x64 (64-bit) versions of SP1.

To install this version, you download an ISO file, burn it to DVD, and then run the Setup.exe application found on the disk. I used this install option on Lenovo ThinkPad T61p, running Windows Vista Home Premium, and ran into no issues.

Note that this version of the installer will not be made available to the public with RC1.

Self-extracting executable

This is an executable that can be run directly on an RTM Windows Vista system to upgrade that system to SP1. There are four different versions: a 5-language version for x86 (32-bit), a 5-language version for x64 (64-bit), a multi-language version for x86, and a multi-language version for x64. I performed this version of the SP1 RC1 install on my Apple Macbook, also running Vista Home Premium.

To install, you download the executable, extract it, and run Setup.exe.

Windows Update

This intriguing version of Vista SP1 RC1 allows you to emulate the experience of upgrading to SP1 using Windows Update, which is the way many Vista users will upgrade in early- to mid-2008. The download is a Windows Update script that changes a Registry key on the PC, thus causing Windows Update to "see" the SP1 RC1 update that's out there in the cloud. (Normally, Vista users would not be able to otherwise access this update from Windows Update.) First, you may need to download a number of prerequisites via Windows Update (which may also require their own reboots.) Then, the process moves along as it does with the other install types. I performed this version of the upgrade on my main desktop, an HP PC running Windows Vista Ultimate. It ended being the most convoluted install of them all, but Microsoft tells me that the prerequisite downloads will have already been installed on most users' PCs by the time the final version of SP1 ships.

The install process

Once you get past the rerequisites, the SP1 install process follows an identical path regardless of which install type you've chosen. You're walked through a simple series of dialogs in which agree to the license terms and click an Install button. A small portion of the install occurs within Windows, but the longest portion occurs after the first reboot: At this point, SP1 runs through a three part installation process that spans multiple reboots. About an hour later, you're presented with the normal Vista Welcome screen and you can use the computer again.

Logging into Windows, you won't notice any obvious changes. This is by design. As I was told in a briefing earlier this week, the SP1 release isn't a major upgrade but is instead a minor update to Vista. It does address feedback from customers and partners in the form of bug fixes, performance improvements, compatibility updates, and other enhancements, but there aren't any major changes, like a new version of Media Center or a new shell. Microsoft's goal is that SP1 shouldn't break any Vista-compatible applications and devices. Customers already had to deal with that sort of disruption with Vista itself, thanks to the many architectural changes Microsoft made to that OS.

Changes from beta to RC

While the overall theme of the service pack hasn't changed, there have been a few small changes since the last beta. The size of the standalone installer has been dramatically reduced, for example: The five-language version is 40 percent smaller now than was the beta, while full 36-language version is over 50 percent smaller.

Microsoft also heard from testers and partners that the SP1 installer didn't provide enough feedback about the required disk space early enough in the process. Now, if you attempt to run the update on a system without enough disk space, the SP1 installer will tell you that early on and let you know how much space needs to be freed up before Setup can continue.

Also, the disk space required to install SP1 has been reduced. Previously, in the SP1 beta, a 32-bit version of the installer would require 7 GB of free space, even though most of that was given back after Setup was complete. Now, in RC1, it requires 4.5 GB or less, depending on your configuration.

Looking ahead

The final change, of course, is that Vista SP1 RC1 will be made available to the public. Users will be able to download the standalone installer and the Windows Update registry key installer beginning next week. Microsoft wants to be upfront that this is still pre-release code and shouldn't be installed on the PCs of typical consumers. But I suspect most people reading this site will have no issues with the RC1 release.

While it's possible that Microsoft will ship other release candidates of Vista SP1 in the future, RC1 is the last major pre-release version. There are no major new features coming, aside from the WGA changes noted above. If you're interested in testing SP1, this is your chance.

Final thoughts

I haven't been using Windows Vista Service Pack 1 Release Candidate 1 long enough to be able to determine its fitness, but previous pre-release builds have been notably stable, and I don't expect to see any major problems this time around. What I'm more concerned with are the perceptions around this update. Folks, Windows Vista is already a stellar operating system, and whether you believe that or not, please don't be misled into believing that SP1 is going to change the overall experience very much. Even in pre-release form, SP1 is solid and stable, but it's not a big change for anyone who's been using Vista all along. That said, this is the latest version of Vista. If you're running this OS, you're going to want to check this one out.