Step One:
Move the mouse pointer to the Instant Eyedropper icon in the system tray.
Step Two:
Press and hold the left mouse button and move the mouse pointer to the pixel whose color you want to identify.
Step Three:
Release the mouse button.
That's it. The clipboard now contains the color code - in HTML format (or any other format that you have previously specified). It can be pasted and used in any text or HTML editor or the Color Picker tool of Photoshop.