Device Manager provides a graphical view of the hardware that is currently installed on the computer. The device drivers and resources associated with that hardware are listed in the properties window of each device. You can open Device Manager by right clicking on My Computer, selecting Properties, and clicking the Device Manager button from the Hardware tab.
One thing you may notice when you open Device Manager are the icons or symbols beside some of your hardware components. Such a symbol would usually indicate that a device is not functioning correctly. However, the type of symbol will give you more of an indication as to what the problem might be. Here is a quick summary of the meaning behind these symbols.
A black exclamation point (!) on a yellow field — Indicates that the device is not functioning properly.
A red “X” — Indicates the device as been disabled.
A blue “i” on a white filed — Indicates the device was manually configured
A green question mark (?) — Indicates that a compatible driver is installed but the device may not have all the functionality available.