If a pair of headphones won't work with your laptop computer, this means that the headphone jack itself has become disabled. If you want to get your headphones working again, you will have to manually enable the headphone jack on your computer using the "Sound" native configuration utility.
Plug your headphones into the headphone jack on your laptop computer. To enable the "Headphone" line on your sound card, the headphones must actually be plugged into the computer.
Right-click on the "Volume" icon in the Windows system tray.
Click "Playback Devices."
Right-click on the listing in the "Playback Devices" window that reads "Headphones."
Click "Enable." Your headphones will now work with your laptop computer.