A little more than one year after its release, Windows Vista will receive its first service pack update in March. Microsoft says the pack will offer better compatibility with third-party hardware, increased reliability, tighter security, and better performance. Our tests disagree

But unlike the last Windows Service Pack release, Windows XP SP2, which offered users a new Windows Firewall, an improved Automatic Updates feature and a pop-up ad blocker for Internet Explorer, Windows Vista SP1 is largely a code update, devoid of new eye candy, and very light on "must-have" features for home users. Most of the features touted by Microsoft are for the Business, Enterprise, or Ultimate editions of the operating system. Our advice: Be patient, and don't download it once it becomes available but wait until Windows Vista SP1 is offered to your PC via Microsoft's Automatic Updates service.

Installation
Windows Vista SP1 will arrive in one of three ways. Most users will automatically receive the update via Windows Update. Microsoft says that users will only receive the changes specific for their computer in order to cut down on network traffic and download times. Users with limited or no Internet connectivity or who need to update more than one PC will be able to download a complete image of Windows Vista SP1 via DVD. And, finally, volume license customers (enterprises) will receive an integrated DVD media package for installation on new PCs.

Before installing SP1, all users running Windows Vista RTM (that is, if you bought your computer with Vista preinstalled) will need to install three updates from Microsoft. Microsoft's Windows Update will automatically detect and install these updates prior to the release of Windows Vista SP1. Two of these updates increase the success rate for installing Windows Vista SP1; one is necessary only if you have Windows Vista Enterprise or Windows Vista Ultimate installed.

While all this sounds complicated, Microsoft insists that it has learned from Windows XP SP2, an upgrade that sometimes stranded users during long, overnight downloads. Windows Vista is modular, thus the upgrade will download only the bites of code necessary for your specific system. If you have enabled Automatic Updates then, in theory, you should have a much shorter download and installation of the upgrade than someone who hasn't kept up with the numerous updates since Windows Vista's release. Despite the many changes within the code, Windows Vista SP1 does not change the basic hardware requirements for running the different editions of Windows Vista.

Using a disc provided by Microsoft, we found the upgrade of Windows Vista to SP1 on a typical Acer Travelmate required about 1 hour. During that time, the computer was unusable and automatically rebooted several times. A display informed us exactly where the install was in terms of overall progress (for example, "Configuring update, stage 1 of 3, 34 percent complete").

Should you, for any reason, want to uninstall this upgrade, Microsoft allows you to do so, although the three preinstallation updates cannot be removed.

Features
As mentioned, where Windows XP SP2 introduced the Windows Security Center and changed the existing Windows Firewall, Windows Vista SP1 introduces almost no visible change to your desktop. There are no new features to view, with almost all of the nearly 300 changes occurring under the hood, and mostly intended for Business, Enterprise, and Ultimate editions.

Specific reliability improvements include the prevention of data loss while ejecting NT file system (NTFS) formatted removable media; enhancements to TCP/IP Version 6 (IPv6); improved driver sleep and wake-up times; improved Meeting Space connections; improved Remote Assistance applications; and it includes Encrypting File System (EFS) in the Windows Vista file-backup set.

For performance, Microsoft claims that SP1 uses less bandwidth when browsing network shares, and automatically selects between wireless and wired when more than one is offered. There are also many tweaks and improvements in ReadyDrive (requires the use of special hybrid drives) and ReadyBoost (requires special USB drives), and SuperFetch (requires a specific amount of RAM). As a result, users currently running Windows SuperFetch will notice that after installing Windows Vista SP1 that their system is slower. Microsoft says that's because SP1 erases the existing SuperFetch data. As new data is collected, the system will respond "within a few days," Microsoft says.

There are many new standards introduced with SP1. For example, there's a new Unified Extensible Firmware Interface (UEFI), x64 Extensible Firmware Interface (EFI) network boot, Direct3D 10.1 for 3D gaming, new flash based xFAT, it identifies HD-DVD and Blu-ray drives as HD drives, supports SD Advanced Direct Memory Access (ADMA), second-generation Windows Media Center Extenders, enhances the MPEG-2 decoder, and enhances support for Windows Network Projector.

For security, SP1 improves the Bitlocker encryption in Windows Vista Enterprise and Windows Ultimate by adding multifunction authentication methods; moreover, Microsoft now allows encryption support for volumes other than the bootable volume. SP1 also includes some Smart Card enhancements, and allows for biometric as opposed to PIN access to Smart Cards. Within Vista, SP1 creates a more secure PIN channel for authentication.

For most home users, the above features will have little or no effect on the day-to-day use of their systems.

Performance
In general, CNET Labs found that Windows Vista SP1 offered a mixed bag of improvements. For example, Microsoft says that reading and writing files will be much faster within Windows Vista SP1. Tests performed by CNET Labs on a Dell XPS M1530 laptop showed that performance did improve in one scenario, remained steady in another, and even deteriorated in a third scenario. When transferring files from one folder to another on the same drive volume, the transfer time did somewhat improve. However, when reading those same files from an external drive, or writing them to the external drive, performance was the same or worse.

File copy times (in seconds)
(Shorter bars indicate better performance)

Write to external HDD

Read from external HDD

Copy files on same internal HDD

Windows Vista Home Premium SP1

75 

52 

61 

Windows Vista Home Premium

52 

51 

65 

Boot and shutdown times (in seconds)
(Shorter bars indicate better performance)

Boot time

Shutdown time

Windows Vista Home Premium SP1

43 

30 

Windows Vista Home Premium

40 

30 

Support
We found that Microsoft offers a reasonable amount of support for the SP1 upgrade. For example, before you start there is a link to a Read Me page called "What you should know before installing Service Pack 1" that covers what to do before installing, during, and after installation. Also, Microsoft has improved the upgrade process itself so that if the installation of one update fails, it tries another while preparing to rerun the failed update. This should speed installation for most users. But if users do run into trouble, they can always uninstall the upgrade.

Conclusion
Do you need Windows Vista SP1? Yes and no. It's always good to install the latest (read: patched) code for any operating system. But downloading and installing the update will take some users a few hours without any visible or tangible improvements to their systems.