ActivateByNum enables Windows 7 task-switching hotkeys on XP and Vista.
[Win]+1 switches to the first window on the taskbar and [Win]+2 the second, etc. It works with only the first 10 windows. The particular window is minimized if it's already active.
For a collapsed group of window buttons, repeatedly pressing the same [Win]+[#] combination will cycle through each window in the group.
[Win]+- shows button numbers (>= 5) as tooltips.
Windows XP (32-bit), Windows Vista (32-bit and 64-bit)