How to fix a computer?

So what you’re saying is that nothing appears on the computer screen, but you can see windows if you drag them over to a connected TV?

It sounds like the computer’s monitor is not working. Is the monitor turned on? If it is, there’s a bunch of different reasons why it might not be working. You could try bringing the monitor to a repair shop or getting a new monitor.

Before trying to fix the monitor – because first it’s important to find out that the problem really IS the monitor, the easiest thing to do if it’s a desktop computer is to see if it will work with a monitor that you know to be working properly. So just plug in a monitor that definitely works, and see what the results are.

If the monitor still doesn’t work with the computer in this case then it’s worthwhile checking the “display options” to see what the settings are for the “main” monitor. If the setup was originally made for a higher-resolution monitor, for example, and you plug in a low-res monitor, then I don’t know what the results will be, but they won’t be acceptable until the settings are within the monitor’s capability range.

Alternatively, there could be idiotically simple things such as the monitor being switched off, the power cable being connected badly, plugged into a dead outlet, etc.