Computer blue screen or stop error: what should you do?

Record the message before trying to fix the machine.

The answer in 2 lines. A stop error can make a computer restart unexpectedly. Photograph the message if possible, allow the restart to finish and note any recent change, such as a new accessory. If it starts normally, protect important files before further troubleshooting. Repeated crashes need assessment, especially if the computer cannot start reliably. An alarming browser message that tells you to telephone support, pay or allow remote access should be treated as a suspected scam.

The first steps

Record the error. Photograph the whole message, including any stop code, without posting personal information publicly.
Let the restart finish. Note whether the desktop returns and whether the same failure happens again.
List recent changes. Record new accessories, software, updates or repairs, and what you were doing when the crash occurred.

Stop: danger

Unexpected support number or payment demand: do not call, pay or install remote-access software in response.
Important files without a backup: stop before resetting, reinstalling, formatting or approving storage replacement. Ask about preserving the data first.
Work or school computer: use your organisation's established support route before changing security settings or recovery options.

A crash or a fake warning?

A genuine system failure can interrupt the whole computer and lead to a restart. A fraudulent warning often appears while browsing, uses alarming language and asks you to call someone or grant access. Colour alone cannot identify either situation. A blank display without an error message may also be a different fault.

Read the police advice on technical support scams: compare the request you received with the warning signs, especially unsolicited contact and demands for remote access. Do not trust contact details simply because they appear beside a convincing logo or technical wording.

What you can check safely

If the computer starts normally, save your work and make a backup before experimenting. Shut down before disconnecting a newly added external accessory, then try starting without it. Keep a note of whether that changes the behaviour. Do not open the case or disconnect internal components as a first step.

Use the computer's own settings to check for available updates, rather than an advertisement promising repairs. The official guidance on keeping devices updated explains why updates matter; use its advice to review automatic updates. This is UK public cybersecurity guidance, although published in Northern Ireland. If crashes prevent updates completing, seek help rather than repeatedly forcing shutdowns.

What not to do

Downloading a cleaner, driver updater or repair utility from an alarming advert.
Following commands from an unknown caller or granting them remote control.
Deleting system files or repeatedly removing updates without understanding the consequences.
Assuming that a recovery option preserves all files, applications and settings.

When the computer keeps failing

A stop code is a clue, not a diagnosis. Hardware, its supporting software or other software can be involved. Record whether failures occur at startup, after connecting an accessory or during a particular task. Tell the repairer about unusual noises, heat or earlier storage problems too.

Use the university troubleshooting guide for its distinction between an isolated crash and repeated startup failures. Its illustrated menus concern older systems: do not assume its keys or menu paths apply to yours. If recovery options appear, stop before a reset unless you understand the effect on your data. Ask a qualified repairer for an assessment when startup remains unreliable.

If you already contacted a suspected scammer

If remote access is active, disconnect the affected computer from the internet. Contact your bank through a trusted route if you paid or exposed banking details. Use a separate trusted device to secure affected accounts, starting with your email. Arrange a security assessment before using the affected computer for sensitive activity.

Open GOV.UK's scam-reporting guidance from a trusted device. Select the route matching what happened; for money lost or an account hacked in England, follow its link to Report Fraud. Save messages, payment evidence and the details of any access granted. Reporting routes differ elsewhere in the UK, so use the location guidance on that page.

Good to know

Use the National Cyber Security Centre's backup guide to choose a backup method and verify the files. Disconnect removable backup storage when it is not in use.
If the computer may have a product fault, approach the seller before commissioning another repair. Use GOV.UK's repairs and refunds guidance to prepare your request with purchase evidence.
Ask a repairer what diagnosis costs, whether data could be erased and whether extra work requires your agreement.

Illustrative example: Aisha's computer begins restarting after she adds an external accessory. She records the error, shuts down and disconnects the accessory. The computer starts normally, so she backs up her files and asks for compatibility advice before reconnecting it. She ignores a repair advert offering a telephone diagnosis.

A made-up story, for illustration.

Bobby

Sources, verification, confidence

Verified on 6 November 2026, for England. Confidence: high for public guidance on scams, backups, updates and consumer rights; medium for general crash troubleshooting. The university source includes older interfaces, so no version-specific recovery sequence is reproduced. Symptoms do not establish the failed component.