Hi,
Sorry to hear you're experiencing this issue.
Error 45 means "Currently, this hardware device is not connected to the computer. To fix this problem, reconnect this hardware device to the computer".
This problem is usually caused by a hardware issue, the problem could be on the connection between the graphics card and the motherboard or a problem in the graphics card itself. The first thing that you can try is to disconnect the graphics card from the motherboard and reconnect it to check if it fixes the problem.
Another possible cause for the problem is an outdated version of Bios, go to your motherboard manufacturer's website and make sure you are using the latest version of the Bios.
If you don't know if you are using the latest version of Bios or cannot find the correct Bios version on the manufacturer's website, provide the full model of your laptop and a screenshot of the system information and I'll be glad to help you find it.
1-Right-click on Start then click on Run
2-Type: msinfo32 and click on OK
You can see at this link how to include a screenshot in your post.