Windows 7 ships with a cool new taskbar (dubbed Superbar) that has big icons, among other things. If you find the Windows 7 taskbar quite big, you can easily reduce its size by making the taskbar icons smaller.
How to reduce the size of the Windows 7 Taskbar or make it smaller?
Right click on any empty area in the Windows 7 Taskbar and choose Properties
Under the Taskbar tab, check the option Use small icons. Click Apply, OK.
You’re done. The Windows 7 taskbar is now smaller, as you can see below.
You now have more area to view other things in your screen, since the size of the Windows 7 Taskbar is much reduced.