Service Pack 3 provides a solid computing experience and is an unobtrusive upgrade to Windows XP. When I first started with build 3244 which is tagged as RC1, it didn't take long for me to make the decision to put this on one of my production machines. This is a heavy work machine as well. This is not a machine that sits in the corner and gets occasional usage. Since these are my first impressions, I was determined not to put it through a heavy battery of testing or performance evaluation. Instead, I decided to use the machine as I normally would every day and see what jumped out at me. Specifications Dell Latitude D620 BIOS Version A08 Intel(R) Core(TM)2 CPU T7200 @ 2.00GHz 2GB PC533 DDR2 Hitachi HTS721010G9SA00 NVIDIA Quadro NVS 110M 256Mb SigmaTel High Definition Audio Software Installed Office Ultimate 2007 Gimp 2.2 Visual Studio 6.0 Enterprise Visual Studio .NET Enterprise Architect Visual Studio 2003 Professional Visual Studio 2005 Professional Visual Studio 2008 Professional SQL Express w/ Advanced Services SP2 Adobe Reader 7.0 Java 6 Update 3 There is other software installed, but these are the applications that get the most usage on a day-to-day basis. Changes and Additions The first thing I noticed was the healthy list of files in the C:\WINDOWS\$NtServicePackUninstall$ directory. There are a total of 3,451 files in this directory. Pretty much all of the system utilities have been upgraded by this service pack. Windows Installer, MS Paint, MMC, PerfMon, VBS engine, even Pinball, this is an all inclusive update. Wireless Oddities I had an odd experience with my wireless connection. One of the security features I use on my wireless is MAC filtering. After installing SP3, my MAC address had seemingly been changed. I could not connect to my wireless and I thought for sure I had made a bad decision and was about to uninstall SP3. I hit my neighbor's router which is completely open and I was able to connect without issue, so I knew it was working. When I started to check my router settings, I noticed that my MAC address for my DHCP reservation and my MAC filter were different than what was on my computer. This puzzled me a little bit. I don't make it a habit of memorizing my MAC address, but I knew that my filtering and reservation was working before I installed SP3. I still don't know what to make of this. I added my ??new?? MAC address to the router and now everything works great, better in fact. Other Features I use Remote Desktop a lot. I have several development and build machines that I maintain and work on. Remote Desktop attempts to verify the publisher of saved connections: After selecting Connect, the connection succeeded without issue. Windows Media Player: Internet Explorer: I never use IE, so I a not 100% sure if there have been any updates to IE 7. Faster? It could be a total placebo effect on my part, but the OS feels much snappier after the installation. I have defienitely noticed a considerable improvement in wireless performance as well. This may have been an unintended effect, but my Intel 3945ABG is performing much better than it used to in my house. Overall, my first impressions are very positive and whether I am developing applications in Visual Studio, editing photos in Gimp, or just browsing the internet, the performance and stability has been outstanding. This is not always the case with a release candidate. This speaks volumes about the pending release version next year. Call me a shill, but I still prefer Vista. What can I say it grew on me.