The new Windows 7 taskbar interface piles multiple windows from the same application behind one another. For some this is a problem, particularly when using Outlook meeting reminders because they can often get tucked away in the pile and you never notice them.
Luckily there is a quick way to revert back to the 'old' way of having a button per window in your task bar. Right click on a blank space on the taskbar, choose Properties and choose Combine When Taskbar Is Full from the Taskbar Buttons dropdown menu.
Hey presto, you now get each window given its own icon, just like Vista / XP.
