Open Your Windows Directories

• Press "Windows Key + E" to open a Windows Explorer application. This shortcut will work in most versions of Windows, including XP, Vista and 7. Repeat the command to open another Explorer panel.
  
  

Navigate to Your Directories

• Click on your desired directory using the file tree on the left side of the Explorer window. Optionally, if you know the path to your directory, type it into the path field at the top of the window. Repeat this for your second open window, for the directory you want to compare. Note that you can switch windows by pressing "Alt+Tab," or by clicking on a different tab in the task bar at the bottom of your screen.
  
  

Position Your Windows

• Click at the top of your Explorer window and drag the window to the side of your screen. Drag your other window to rest beside the first one. If your monitor is small, click the right or left edge of the Explorer window and drag it left or right to re-size the panel horizontally and make it fit in your resolution. Increasing your monitor resolution can also help to fit more on your screen.
  
  

Comparing Directories

• Click inside the directory contents panel (on the right side of Windows Explorer) and select "View." From this drop-down option you can select a detailed view with more information, such as the date that your files were last modified, or the type of file that they are. You can also select from a number of different views, depending on the kind of information you're seeking. Columns can also be sorted according to different criteria by clicking on the top row, where it lists the name and other details. Choose the settings you want and with each window side by side you can compare your directory contents.