Reloading Win7 Ultimate system host plug-in headphones without sound but looks like everything is normal

A few days ago, I just reinstalled the system, installed win7 Ultimate, but found that my headphones have no sound, the bottom right corner The speaker icon is not crossed, it is normal, and the sound card driver has nothing wrong with it, that is, there is no sound? What is going on?

Specific steps: (headphones are normal)

1. Click on the mouse "Start" and click on Control Panel & mdash; select <;Hardware and Sound". As shown in Figure 1
Figure 1 Hardware and Sound

2. In the "Hardware and Sound" interface, select "Realtek High Definition Audio Manager", as shown in Figure 2. Br>Figure 2 Realtek High Definition Audio Manager

3. In the “Realtek High Definition Audio Manager” interface, click on the “Yellow File” button, as shown in Figure 3. > Figure 3 Click “Yellow File”

4. In the “Encryption Settings” dialog box, tick “Disable Front Panel Jack Detection” and press OK. As shown in Figure 4
Figure 4 Disable front panel jack detection

After setting, the headphones will sound.