Hello Alejandro,
Let us isolate the issue by answering the following:
- Have you tried connecting another headphone on your PC to make sure that the port is working properly?
- Do you get any error message when using your headset?
You may also try to perform the following troubleshooting steps below:
Run the fix it for hardware devices and check if you will still encounter the same issue.
Perform clean boot to start Windows by using a minimal set of drivers and startup programs. This helps eliminate software conflicts that occur when you install/run a program on your OS. Refer to this link to perform the clean boot in your Windows 7.
Thanks.