Windows 7 Milestone 3 Build 6801 is the build that was given out at the Microsoft PDC from October 27, 2008 through October 30, 2008. Windows 7 Milestone 3 was jsut 1 of many items given out at the conference. This build was also released to several Pre-Beta testers.
This Build is different than the Build shown at PDC. The Build shown at PDC was 6933. This Build is older and complied on October 20, 2008. Just day before the PDC began. What makes this so significant is that this build still highly resembles Windows Vista with it's looks and feel. The GUI is almost identical to Windows Vista in just about every way with minor changes and tweaks found throught out the OS.
The biggest change first noticed is the different style of tasbar. While not as apparent as the Build at PDC the new on in Milestone 3 shows where they are going with the new look and feel. It is much more condensed and fluent. Gives the user more space to work with in their taskbar while not cluttering it up with icons and shortcuts. The next item noticed is actually a item that is missing. The Sidebar. One of the biggest features added to Windows Vista is gone? Not quite.
While the actual sidebar itself maybe gone. The Gadgets are not. They are now desktop gadgets. They can be used just like the sidebar gadgets but without the sidebar. While in Windows Vista could be moved and placed anywhere the reason this is so big is that they are not dependent on the Sidebar running. As of currently if you run a desktop gadget, you will notice that there is still the sidebar.exe file running in your task manager.
There was work done to the amount of themes and how themes work together with the Aero interface and backgrounds. They have several pre-built theme packs already and of course there is the option to customize the package for you personal tastes. There is also doulbe the amount of Aero Themes now. Many more colors for Aero are available upon install.
One major thing that many people will notice is the new UI for some old items. Such as Paint. It now has the "Ribbon" feel to it from Office 2007. While the "Ribbon" look has been both highly praised and highly critized it is unknown at this time how this change will affect the overall performance of such items as Paint.While the new interface is nice it should not cost us more in resources to run it. It was light weight before and looked just fine. It needs to have a major overhaul to be more than just a program used to drop a screen shot every now and again.
The major question everyone has is performance. Sadly at this time there is no way to give a definate answer as to a yes or no if Windows 7 is better. The code itself isnt optimized yet, and the build that is being tested is still very much like Vista. There isnt much more that can be said about it cause if you have run Windows Vista you have gotten close to how the current status of Windows 7 is right now.