In Windows XP, users have a choice of the default Start Menu type or the "Classic" Start Menu, which was introduced in Windows 95. My personal preference is the "Classic" Start Menu due to its simplicity and it's the way I am used to working with Windows for the past 14 years or so.
Here's the XP Default Start Menu. Even though I prefer Classic, the XP default is still pretty clean and easy to understand. The "Run" icon to execute command-level options (such as the CMD.EXE command prompt) is also present.
Windows XP Classic Start Menu
And here's Classic. Nothing could be simpler. As with Default, Classic has a Run icon.
Windows 7 Build 7000 Start Menu
Here Windows 7 build 7000. Many users will be bypassing Vista entirely, so this Start Menu is a dramatic change, especially from Classic. This has some resemblance stylistically to XP's default Start Menu but it has enough changes to make things confusing for a lot of users. The Shut Down button is hard to see against the rest of the text, it should have a prominent red button to identify it. Notice also that the "Run" option is also missing, which will annoy many power users.
Run Command thru Search in Windows 7 Build 7000 Start Menu
To get to the Run command, you actually have to do a Search on "Run" for the icon to pop up. One of the first things I did was drag the icon to the desktop. Annoyingly, you can't drag the "Run" icon to the taskbar, like you can do with other programs, such as Firefox.
Windows XP Start Menu Customization
Here is the Advanced Options dialog for "Customize" for the XP Start Menu. There's a lot of options here, but it's easy to understand. It takes 3 clicks to get to this menu, Right click Start, choose Customize, and click on Advanced Tab. Most end-users probably wouldn't mess with most of these settings, it's the type of stuff that would usually be rolled out with System Policy in a large organization.
Windows 7 Build 700 Start Menu Customization
Here is the Start Menu Options dialog for Windows 7. Like XP, it is 3 clicks away, but they've changed the naming and the navigation, which makes it confusing. It's now right click Start, choose the Start Menu tab, and click on Customize.
Windows XP Desktop Customization
Everyone is familiar now with the modern Windows desktop paradigm that's been around since 1995. Since Windows 2000 arrived in 1999, everyone's cozy with My Documents, My Computer, My Network Places and Recycle Bin. On many OEM XP deployments these icons are readily accessible and are already on the desktop, but you can choose to add and remove them as you need to. You can get to them on XP by right clicking on the desktop, choosing "Properties", clicking on the Desktop tab and choose "Customize Desktop". We've been doing things this way since 2001, and we all know these menus and dialogs like the back of our hands by now.
Windows 7 Build 7000 Desktop Customization 1
With Build 7000 of Windows 7, Microsoft decided to give end-users a clean slate on their destkop instead of their familiar navigation icons. Out of the box, you have to get to your favorite places from the new Start Menu, which will leave many veteran Windows users confused and frustrated. You can put them back, but it's not intuitive. You have to right click on the desktop and choose "Personalize" (a naming convention change from Properties) and then click on "Change Desktop Icons". This is a change that was introduced in Windows Vista, but again, many users will experience this first with Windows 7.
Windows 7 Build 7000 Desktop Customization 2
Arguably this is less mouse clicks than XP, but it's still a change. I also think that taking away the icons and making the end-users put them back manually is a bad decision. I also don't like the name change of the root folder "My Documents" to the default user name, which is a change that was introduced in Windows Vista.
Windows XP Control Panel
Here's the Windows XP Control Panel that we all know and love -- seasoned Windows users know how to get to it quickly and they know where everything is.
Windows 7 Build 7000 Control Panel 1
Here's Windows 7's Control Panel. I can see why Microsoft did this so as to introduce simplicity by grouping functions, but for a veteran user, it's frustrating. It also requires an additional click to see all the menu items. Hovering over each menu item yields a text description that you need to read to see what is contained below, however, I think they could have simply had the other icons from the next level down appear for each grouping when you hover, or use a paradigm similar to the MMC where you have an expandable tree list.
Windows 7 Build 7000 Control Panel 2
Here's all the Control Panel icons in Windows 7. Arguably there's a lot more icons here than in XP, but they could have done some more consolidation and organized it a bit better.