I frequently have 10 or more windows of the same application (e.g. Outlook, Word, IE, etc.) open at one time. Windows 7's new taskbar grouping thumbnail feature shows a preview of open windows (aka thumbnails) when you single-click on the taskbar group for that application.
But when I have over 10 windows open (more thumbnails than will fit horizontally on my screen), Windows reverts to a vertical menu. This is disconcerting since I need to train myself to deal with two separate behaviors and can never anticipate what I'm going to see when I click on a taskbar group.
Furthermore, I find the thumbnails more difficult to visually scan through (vs. the vertical menu) because only 1-2 words of each window's title are shown. Typically that's not enough text to disambiguate and help me find the right window.
I'd like to force Windows 7's taskbar grouping to always show a vertical menu (like in XP) instead of sometimes showing thumbnail previews and sometimes showing a vertical menu.
Anyone know how (whether?) this can be done?
UPDATE: BTW, I'm running the RTM version (build 7600) of Windows 7. There are apparently other solutions out there which work on earlier builds, but which don't work on the RTM build.
Best Answer
There's a registry key you can edit to get this behaviour even in modern versions of Windows 7:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Taskband
Create a DWORD called NumThumbnails, and set it to 0 to achieve list mode for all taskbar groups.
Alternatively, you can set it to a number such as 3 or 4. Then apps with that many or fewer windows will use the thumbnails interface, but apps with more than that many windows will use the list mode.
This is my preferred setup, so that things like Outlook and Word still use thumbnails when I have 2-3 windows open, but Chrome and Windows Explorer (for which I typically have 10-15 windows open each) use the more informative list mode ("vertical menus").
Source: http://www.sevenforums.com/tutorials/75804-taskbar-list-thumbnail-previews-mode-change.html