So I wanted to connect my second monitor to my laptop HDMI.
Unfortunately, this is not recognized.
I have windows 8.1 pro and bottom right is Windows permanently enabled.
Could it be because of that?
No, the activation is not.
Does your notebook have a monitor connection (HDMI, VGA, DisplayPort)?
Too little information.
Yes, I tried to connect my monitor with Hdmi, but does not work.
What information do you need?
Now is not the topic of the question, but I would really recommend you to switch to Windows 10.
I get along with Windows 8.1 pro 😉
Does your laptop have an external graphics card? Have you ever tried another cable? And have you tested whether, for example A TV is detected?