A+: Troubleshooting with Device Manager
If your computer has devices that are malfunctioning in a way that Device Manager can detect, or has devices that are disabled, they will be displayed as soon as you open Device Manager. If the Ports (COM and LPT) category displays a malfunctioning port, COM 2, displays an exclamation mark (!) in a yellow circle. The parallel printer port, LPT1, if disabled, shows a red X. If the malfunctioning or disabled device is an I/O port, such as a serial, parallel, or USB port, any device attached to that port cannot work until the device is working properly.
Not every problem with a device shows up in Device Manager, but most problems with resource conflicts or drivers will be displayed there.
To troubleshoot problems with a device in Device
Manager, open its Properties sheet by double-clicking the device. Use
the General tab to display the device’s status and to troubleshoot a disabled or
malfunctioning device. If the device’s General
Properties sheet lacks a solution button, look up the Device Manager
error code and take appropriate action manually.