To make your taskbar transparent -- and more appealing -- you need to enable the Windows Aero tool. When you enable transparency, the margins of all windows, as well as the Start menu, become transparent. To ensure Aero works on your system, install the latest drivers for your video card and then run the Aero Troubleshooter. After you enable the transparency option, you can change the color and color intensity for the taskbar, windows and Start menu.
Click the Start button, type "Aero" into the Search box and then select "Find and fix problems with transparency and other visual effects" in the list of results.
Click "Next" when the troubleshooter displays to start searching for problems with Aero. The process may take up to five minutes; don't close the troubleshooter until it finishes scanning for problems.
Select "Close the troubleshooter" when you see the "Troubleshooter couldn't identify the problem" message. If the troubleshooter detects some problems, it automatically tries to fix them.
Right-click on a blank spot on the desktop and select "Personalize" from the context menu to open the Personalization section of the Control Panel.
Select a theme from the Aero Themes section and then click the "Windows Color" link. The Transparency option is not available if you select a Basic, Classic or High Contrast theme.
Check the "Enable transparency" box to make the taskbar, windows and Start menu transparent. Make the taskbar more or less transparent by dragging the "Color intensity" bar to the left or to the right. Click "Save Changes" to apply and save the new settings.
Change the color of your windows, Start menu and taskbar, by selecting a different color. To create a custom color, click "Show color mixer" and then use the "Hue," "Saturation" and "Brightness" bars to customize the color. Click "Save Changes."