If your computer screen suddenly goes black, freezes completely, or restarts on its own without warning, it can be alarming. These problems have a range of causes, most of which are fixable. Here is how to work out what is happening and what to do about it.
When the Screen Goes Black But the Computer Is Still On
If you can hear the computer running but the screen is black, the issue is often the display connection rather than the computer itself.
- Press a key or move the mouse — your screen may simply have gone to sleep. If the screen wakes up, it was probably only asleep.
- Check that the cable connecting your monitor to your computer is plugged in firmly at both ends. If the picture returns after this, a loose connection was probably the cause.
- If you have an external monitor, try pressing the brightness up key on your keyboard.
- Try pressing Windows key + Ctrl + Shift + B — this restarts the graphics driver on Windows and often fixes a blank screen. If the screen comes back after this, the graphics driver was probably the cause.
When the Computer Freezes
A frozen computer — where the mouse will not move and nothing responds — usually means a program has crashed and taken over the system.
- Wait one or two minutes. Sometimes it resolves on its own.
- Try pressing Ctrl + Alt + Delete and opening Task Manager. If the Task Manager window opens, the computer is still responding, so the problem may be limited to one program. Look for any program that says Not responding and end it.
- Warning: holding the power button can lose unsaved work and damage files. If the screen still responds, save your work first. If nothing responds, wait a few minutes. Only as a last resort, hold the power button for about five seconds until the computer shuts off. Then turn it back on.
When the Computer Restarts by Itself
Unexpected restarts are often caused by a Windows update that needed to finish installing, overheating, or a driver problem.
- Check if there are pending updates — Windows sometimes restarts to finish installing them. Windows 11 version 24H2 Home and Pro editions stop receiving updates on 13 October 2026, so check which version you have and plan an update before that date if you use one of them.
- Make sure your computer has room to breathe. Dust blocking the vents can cause overheating and trigger a restart. Use a can of compressed air to gently blow dust out of the vents.
- If it happens repeatedly and often, it is worth having a technician look at the hardware.
When to Seek Help
One or two unusual events can happen to any computer. If these problems happen regularly — more than once a week — something needs attention. A computer repair shop can run diagnostics that reveal hardware problems you cannot see yourself.
Keeping notes about when and how these events happen makes it much easier to describe the problem to someone who can help.
Last updated: October 9, 2026