Windows Vista SP2: What to Expect

I've gotten a number of emails about Microsoft's next major update to Windows Vista with SP2. Although I published a short description of this service pack on the SuperSite for Windows before Microsoft announced SP2 last October, I'm embarrassed to admit that I haven't provided any substantial updates since then--which is particularly odd because I've been using various versions of SP2 with Vista on a Lenovo ThinkPad SL500 since last fall. So let's take a look.

First, Microsoft will almost certainly ship SP2 to the public in April. This follows three major prerelease milestones, including Beta 1 in late October 2008, Beta 2 in December 2008, and, most recently, RC1 late last week. I've installed each of these releases, in turn, on that Lenovo laptop, on which I also test the Internet Explorer 8.0 RC build.

Before getting into the functional changes in Vista SP2, I should point out that this release will be a shared, common update between Windows Server 2008 and Vista. This is possible because Microsoft has now aligned its client and server OS releases--so when Server 2008 shipped last year, it did so with the code for SP1 included. Moving forward, customers will have a simpler task of testing and deploying service packs. (This release also creates the strange situation in which SP2 is the second service pack for Vista, but the first for Server 2008. But I'll try not to dwell on that.)

From a functional standpoint, SP2 is nothing like Vista SP1. That is, it doesn't include major functional, reliability, or performance improvements. Instead, SP2 is largely a traditional service pack, aggregating all of the hotfixes and other updates that Microsoft has released since SP1. (And yes, as a result SP1 is a prerequisite for installing SP2.) Thus, Server 2008 SP2 and Vista SP2 systems should be almost completely compatible with software and drivers written for Server 2008, Vista, and Vista SP1.

That said, SP2 does include some minor functional updates. After all, time marches on, and Microsoft needs to address emerging trends when possible. Functional updates in SP2 include:

In addition to the changes noted above, some SP2 changes are Server 2008-specific. For example, whereas the original shipping version of Server 2008 included a prerelease version of the Hyper-V virtualization solution, the final shipping version of Hyper-V 1.0 is included in SP2. (Customers could previously download this version for free.) And Hyper-V brings with it one free guest OS installation with Server 2008 Standard Edition, four free licenses with Server 2008 Enterprise Edition, and an unlimited number of free licenses with Server 2008 Datacenter Edition. SP2 also cleans up some Terminal Server license key issues.

Finally, SP2 includes a service pack clean-up tool (compcln.exe) that permanently deletes older versions of the RTM- and SP1-based files that SP2 replaces. Employing this tool can save disk space, of course, but it can also be used to reduce the size of future installation images.

If you're interested in testing SP2 and aren't on the beta list, Microsoft will likely make the RC1 version available via MSDN and TechNet soon. (The December Beta 2 release is currently available.)