Now that Windows XP SP3 is arriving, is there really any good reason for a business to "upgrade" to Windows Vista? Ah ... I can't think of one.

I've been running XP SP3 and Vista SP1 since they were in late beta. At the moment, neither XP SP3 nor Windows Vista SP1 are available to the general public due to a problem with a Microsoft retail program. Once the update system is set to not upgrade systems with that software, Microsoft promises to turn the spigot back on for these service packs.

While I haven't done any benchmarking with either one, I have lived and worked with both service packs. The difference between the two operating systems plus service packs is like that between day and night. Windows XP SP3 is the best Windows PC operating system I've ever used. In contrast: Windows Vista SP1 will finally run on one of my computers without any ongoing problems. That's the best I can say for it.

Enough with generalities. Here's what I've found in working with the pair over the last few months.

Window XP: Did You Say It Was a Pleasure to Upgrade?!

I used two test systems. One was an upgraded Gateway 503GR. This system uses a 3GHz Pentium IV CPU, 2GB of RAM, an ATI Radeon 250 graphics card, and a 300GB SATA (Serial Advanced Technology Attachment). My other PC was a stock HP Pavilion a350n. This system has a 2.6GHz Pentium 4 processor, 512MB of dual-channel DDR333 SDRAM (synchronous dynamic RAM) and a 120GB SATA hard drive. In other words, they're state-of-the-art 2005 systems. Your offices are probably full of systems of a similar vintage: too new to replace, too underpowered for Windows Vista.

The service patch installation from its compressed 350MB executable download took less than half an hour on the 503GR. It was a much slower process on the a350n. It took slightly less than two hours. The problem is that the patch update uses a lot of memory. With 2GB of RAM, there was no swapping to the disk; with 512MB, the hard disk light was almost never off.

First, hard benchmarks aside, it certainly seemed to me that SP3 made Windows XP and its applications livelier than they had been under XP SP2.

As I worked with the two operating systems, I noticed that Windows XP SP3 is a more of a rollout of updates than the dramatic change in functionality that XP SP2 was. For instance, XP SP3 doesn't come with Internet Explorer 7 (IE7) and Windows Media Player 11. If you have them installed, it does include the latest patches for those applications. Since many Web-based applications still expect IE6, that's fine as far as I'm concerned.

The one truly new XP SP3 feature is Network Access Protection (NAP). NAP, which works with Windows Server 2008, is a security checkup protocol. It blocks any PC from joining a Server 2008-based active directory (AD) unless it meets the server's security update policy standards. For example, if the server requires a PC to have the latest patches installed, it won't let the PC login until it has gotten those updates.

XP SP3 also makes some needed improvements to older management and security programs. For example, it includes Microsoft Management Console (MMC) 3.0 and Windows Installer 3.1. It also brings existing protocols up to date. For instance, Wi-Fi networking now supports the new and improved WPA 2 (Wi-Fi Protected Access version 2) for security.

There's another change I really liked a lot—as someone who can never find a product key when he needs one or who mistypes it, given half a chance. When you upgrade from a network share or from a CD rather than by using Windows Update, you don't need to re-enter the operating system key. Since I always update from a local network share when I'm dealing with multiple systems, this is a win-win as far as I'm concerned.

Once in place, XP SP3 got along well with my existing hardware and software. Over the last few months, I've run Microsoft Office 2007, Microsoft Office 2003, OpenOffice 2.4, Thunderbird 2.0.1x, Firefox 2.0.1x, Adobe Photoshop CS3, Adobe Photoshop Elements 6, Intuit Quicken 2008 and a host of other programs. Without a single hitch.

The bottom line? After a few days of working with the SP3 late beta I went ahead and updated all my XP systems to this patch. It was that good.

Since then, as SP3 starts and stops its way to its full release, I've gone ahead and updated to the RTM (Release to Manufacturing) version. It's been the smoothest, most significant Windows upgrade I've ever had the pleasure of making. Yes, I said "pleasure."

And then there's Vista.