If you disable your graphics card in Device Manager and your display goes black, it's usually because the system can't output a signal using the disabled graphics card. To solve this problem, you can try the following methods:
Restart your computerFirst, try restarting your computer. If the computer has a black screen because there is no available graphics card, a reboot may trigger the recovery mechanism of Windows.
Enter Safe Mode
Forwindows 10/11, you may need to force restart multiple times (press and hold the power key on until your computer shuts down and then turn it on again) to trigger advanced boot options. From here, you can select "Troubleshooter> "Advanced options" > "Startup settings" and then restart, and choose to enable "Safe Mode".
In Safe Mode, Windows will boot with minimal configurations, usually using the basic drivers, which means that even if the main graphics card is disabled, you will still be able to see the screen.
Enable the graphics card: Once in safe mode, open "Device Manager", find the disabled graphics card, right-click on it, and select "Enable Device".
If you have an integrated graphics card on your computer's motherboard (especially on a desktop with a discrete graphics card):
Turn off your computerto disconnect the power supply.
Unplug the discrete graphics card(if you can) orConnect the monitor to the ** output port on the motherboard, not the output port on a discrete graphics card.
Restart your computer, the system should automatically use the integrated graphics output** signal.
Go to Device Managerto re-enable the previously disabled graphics card.
If none of the above solves the problem, you may want to consider using Windows Recovery Environment (WinRe) for a system recovery or reset
You can force reboot multiple times to get into Winre when you boot up, then select "Troubleshoot", >"Reset this PC", or "Advanced Options" > "System Recovery".
Note that resetting or restoring your system may result in data loss, please back up important data as much as possible before performing these operations.
When dealing with these types of issues, make sure to follow safe operating procedures, especially when dealing with hardware such as unplugging and unplugging a graphics card. If you're not confident in your technical abilities, seeking help from a professional may be a safer option.