Many of us do not like our taskbar cluttered with multiple applications that are running. To overcome this problem, Windows uses the automatic grouping feature that automatically groups two or more windows of the same program and labels the group with the name of the parent application. However, if you would like window grouping to take place only after a specific number of windows have been opened, you would have to tweak your registry settings. Once done, Windows will start window grouping only after a specific number of windows of the same application are open. Follow these steps to enable task bar grouping after a specific number of windows are open:
Download the registry file from http://www.mediafire.com/?cyzyz4mzgim. This registry file can be used with Windows Vista as well.
Double-click the registry file to add the contents to the registry.
Restart your system.
Now click 'Start', type 'regedit' in the 'Search' box and press [Enter].
Go to registry folder->
You will be able to view the 'TaskbarGroupSize' registry key.
Double-click it, type an appropriate integer and click 'OK'. If you type the integer '5', Windows will start automatic grouping after five windows of the same application are open.