Windows 7 Navigation Buttons Customizer is a freeware from door2windows that allows you to change the navigation buttons in Windows 7.
How To Use:
Run the tool as administrator.
Select the bitmap that you want to change.
Click Change Selected Bitmap.
Select the new bitmap and click Open. If you don't have any bitmaps, get some from here.
Now the Windows Explorer will restart and you will be able to see the new bitmap.
After you change all the bitmaps, you'll get a cool look:
To restore any bitmap, just select the bitmap and click Restore Selected Bitmap.
In case anything goes wrong, just follow the steps in the following link to restore everything back to default easily: http://www.door2windows.com/windows-troubleshooting/