Blue screen errors: what they mean and what to do

A blue screen (also called a stop error) means Windows hit a problem it could not safely carry on from, so it stopped and restarted. Read the message and work through the fixes that Microsoft recommends, starting with the least risky.

Before you start

One blue screen on its own is usually not a cause for worry. Microsoft notes that many unexpected restarts do not come back. Start digging only if the same error repeats, or if the PC crashes every time you use it.

On some newer versions of Windows 11 the error screen may be black instead of blue. The steps in this guide are the same either way.

If the PC still starts and runs, copy your important files to another drive or to the cloud first. See how to back up your files and create a restore point.

Read the message

Look at the bottom of the screen. Windows shows a stop code, which is a short name in capital letters such as PAGE_FAULT_IN_NONPAGED_AREA. It may also name a file or module that was running at the time. Photograph the screen or write the code down. A code can point to a likely cause, such as a driver (the software that lets Windows talk to a piece of hardware) or the memory.

Do not call a number or install anything because a pop-up or a web page claims to be a blue screen. A real blue screen is a full-screen Windows message that appears by itself. A web page cannot create one that you cannot close. See what to do about a fake virus pop-up.

Try these fixes in order

Fix 1: Remove hardware you added recently

A new device or a faulty cable can cause crashes. This takes about 3 minutes.

1. Shut down the PC.
2. Unplug anything you added shortly before the problem began, such as a USB drive, printer, webcam or new internal part. Leave the keyboard and mouse connected.
3. Start the PC and use it as you normally would.

If the crashes stop, the device or its driver is the cause. Plug it back in later and check the maker's website for a driver for your version of Windows.

Fix 2: Start in Safe Mode if Windows will not run

Safe Mode starts Windows with only the basic drivers, which lets you make fixes when the PC crashes during normal start-up. If Windows starts normally, skip to Fix 3.

1. If you can sign in, open Settings then System then Recovery on Windows 11, or Settings then Update & Security then Recovery on Windows 10. Next to Advanced startup, select Restart now.
2. On the blue menu, select Troubleshoot then Advanced options then Startup Settings, then select Restart.
3. When the list appears, press 4 for Safe Mode, or 5 for Safe Mode with Networking if you need the internet.

If Windows cannot start at all, see Windows stuck in an automatic repair loop or PC will not turn on.

Fix 3: Install Windows updates

Updates often include fixes for drivers and for crashes. This takes 5 to 30 minutes.

1. On Windows 11, open Settings then Windows Update. On Windows 10, open Settings then Update & Security then Windows Update.
2. Select Check for updates, install what is offered, and restart when asked.

If updates will not install, see Windows Update stuck or failing.

Fix 4: Check Device Manager for a flagged device

1. Right-click the Start button and select Device Manager.
2. Look for a device with a yellow exclamation mark. Expand the categories if needed.
3. Right-click that device and select Update driver, then Search automatically for updated driver software.
4. If the crashes began right after an update, right-click the device, select Properties, open the Driver tab and select Roll Back Driver if it is available.

Get drivers only from Windows Update or from the PC or device maker's own website. The full steps are in fix driver problems with Device Manager.

Fix 5: Check free space and memory

Microsoft advises keeping roughly 10% to 15% of the drive free. Open Settings then System then Storage to see how full the drive is, and see how to free up disk space if it is nearly full.

Faulty memory (RAM) can also cause stop errors. To test it with the tool built into Windows:

1. Save your work. Select the search box on the taskbar and type Windows Memory Diagnostic, then open it.
2. Select Restart now and check for problems. The PC restarts and runs the test, which can take several minutes.
3. When Windows starts again, the result should appear in a notification. If it reports errors, or no result appears, ask the PC maker about the memory.

Heat can also cause crashes, especially during games or video. See PC overheating or loud fans.

Fix 6: Go back with a restore point

A restore point returns Windows system files, settings and installed programs to an earlier date. It is meant to leave your personal files alone. It only works if System Protection was turned on before the problem began.

1. Press Win + R, type rstrui.exe, and press Enter. Or open Control Panel then Recovery then Open System Restore.
2. Select Next. Choose a restore point from a date before the crashes began. Select Show more restore points to see older ones.
3. Optionally select Scan for affected programs to see which programs will change.
4. Select Next, then Finish. Windows restarts to apply it.

If System Restore is empty, see how to create restore points so you have one next time.

If it still crashes

• Write down the stop code and when the crash happens, for example while gaming, printing or waking from sleep. That detail helps a technician.
• Use the support page on your PC maker's website for your model number. It lists drivers and a firmware (BIOS) update when one exists. Install a firmware update only if the maker says it applies to your model.
• A failing drive can also cause blue screens. If you hear clicking, or files go missing, back up at once.
• If nothing works and your files are safe, Reset this PC is the last resort. It is under Settings then System then Recovery on Windows 11, or Settings then Update & Security then Recovery on Windows 10.

Frequently asked questions