As you open more and more items in Windows, all of the Taskbar buttons eventually need to shrink a bit to make room for the new button. If you open more than one item using the same program, the “individual” taskbar buttons might eventually collapse into a single taskbar button that displays a number.
For example, suppose you open several Windows Explorer folders from the Start menu: My Documents, My Music, My Pictures, My Computer. If the taskbar becomes too crowded, the taskbar buttons for those folders may collapse into a single button labeled “4 Windows Explorer.” The number 4 means that there are “four open folders.” Windows Explorer is the name of the program that lets you navigate around in, and view the contents of, all the folders on your computer.
Note: Do not confuse Windows Explorer with Internet Explorer. Windows Explorer is the program that lets you explore things inside your own computer. Windows Explorer opens automatically whenever you open any folder. Internet Explorer lets you explore things “outside” your computer – specifically things on the Internet.
When you click on a taskbar button that represents multiple open items on your desktop, a small menu pops up, as shown below. To bring one of those items to the top of the stack of items open on your desktop, just click its name in the menu. Or, if the item is already visible on the desktop, clicking its name will minimize the item to hide it from view for the time being.
As you close items on the desktop, freeing computer memory and making more room for taskbar buttons, a collapsed button might suddenly “un-collapse,” breaking out into separate buttons again. This is normal. It is Windows optimizing the available Taskbar space.
Tip: At any time, you can neatly stack all of your open program windows on the display like sheets of paper. To do so, right-click the current time display in the lower right corner of you screen, and then select “Cascade Windows” in the menu that appears.