Disable or customize taskbar grouping (XP)

Right-click the taskbar, and select Properties.
Uncheck Group similar taskbar buttons.

Customize taskbar grouping

The taskbar buttons are grouped when you have three or more windows of the same

program open. You can change this

value:[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Advanced

"TaskbarGroupSize"=dword:00000003

"00000003" is the default value. Change it to what you want.