So, installing Vista SPI shouldn't cause any problems ¬but why bother? Although Microsoft provides plenty of information on what SPI does, this information is rather technical and the official guide to what's changed runs to 20 pages. The truth is that anyone who expects a radical change of the type seen with Windows XP SP2 is likely to be disappointed. The most obvious change is that the Search item has disappeared from Vista's Start menu, although the search box is still in place. This is because Microsoft has changed the way Search works so you can, if you wish, install a different search tool from a company such as Google to use instead. To launch the Search window after installing SPI, simply press the Control and F keys together.

Microsoft isn't claiming that Vista SPI will provide a major speed boost, although it does say that an error in the way files are copied has been fixed. Before SPI, Vista would sometimes take a while to calculate how long it would take to copy a file, but after installing SPI the process should be significantly speedier. There are other subtle improvements, too.

The Disk Defragmenter tool, for example, now allows you to choose which disks to work on, rather than defragmenting every one of them. Users of Windows Vista Ultimate will also find that the Bitlocker encryption tool, which scrambles the contents of the disk to keep them from prying eyes, is now able to work on all hard disks, rather than just the one with Windows stored on it.



Microsoft also claims that SPI will improve reliability. This is extremely difficult to test, but we used the pre¬release version of SPI daily for four months and didn't suffer any failures. Before SPI the same system was freezing at least half a dozen times a month, so Microsoft certainly appears to be making steps in the right direction.

Our Verdict
Ultimately, nobody will be forced to install Vista Service Pack 1. At the time of writing, only those who choose to install the update will get it, and even after Microsoft starts delivering SPI automatically via Windows Update, there's a free Microsoft tool that will prevent PCs from installing it - for more information, see Microsoft's website at Download details: Windows Service Pack Blocker Tool Kit.

Unless you have a specific reason to do so, though, we recommend checking the list of problematic programs (see the 'Problem programs' box) and, if none of yours is listed, choose a time to update at your convenience. This will ensure you have the hour or so required for the update to complete successfully.

When you are ready to install SPI, use Wmdows Update to get the smallest, safest version: click Start, then Control Panel, then select Check for Updates. After starting the installation process, do not attempt to use any other programs or shut down the computer; instead, make a cup of tea and leave your PC alone for the process to complete.