10 Warning Signs Your Laptop or PC Needs Professional Repair in 2026

Your laptop's cooling system — a combination of internal fans, heat pipes, and thermal paste — is designed to keep the processor and graphics chip within a safe temperature range under load. When the fan is running constantly at high speed even during light tasks like browsing or writing documents, or when the bottom of the laptop becomes uncomfortably hot to the touch, the cooling system is struggling to do its job.

In the short term, overheating causes thermal throttling — the processor automatically reduces its speed to generate less heat, making the laptop noticeably slower. In the medium term, sustained high temperatures degrade components — particularly the battery and the solder joints on the motherboard. In the long term, an overheating laptop that is not addressed will eventually suffer a catastrophic thermal failure — and that failure is often not reversible.

How to check your actual temperatures:

Download HWMonitor (Windows, free) or use iStatMenus (Mac) to see your CPU and GPU temperatures in real time. This tells you whether you are dealing with an actual overheating problem or simply a normal, functioning cooling system doing its job under load.

Common causes of laptop overheating:

• Blocked vents: Dust accumulates inside the laptop over time, clogging the heat sink and vents until airflow is severely restricted. This is the most common cause of overheating in laptops that are two or more years old.
• Degraded thermal paste: The thermal paste between the CPU and its heat sink dries out and becomes less effective over time — typically after three to five years. When this happens, heat transfer from the chip to the cooling system becomes inefficient.
• Failing cooling fan: The fan itself can wear out, become blocked by debris, or develop a fault that causes it to run at incorrect speeds — either too slow or, in some failure modes, not at all.
• Blocked vents from use position: Using the laptop on a bed, sofa, or cushion that covers the bottom vents is a common cause of sudden overheating — though this does not require professional help, just a different surface.

The Blue Screen of Death — Windows' crash screen that appears when the operating system encounters an error it cannot recover from — is one of the most alarming things a laptop can display. A single BSOD, particularly after a driver update or major Windows change, is not necessarily a crisis. But recurring BSODs — two or more in the same week, or BSODs that happen during the same type of task repeatedly — always indicate a problem that needs investigation.

In 2026, Windows 10 and 11 BSODs show a QR code and a stop code. The stop code is the key piece of information — it tells you (and any professional you consult) exactly what caused the crash.

The most important BSOD stop codes and what they mean:

How to find your BSOD history:

This is the warning sign that should make you stop everything and take action immediately. A clicking, grinding, or rhythmic scraping sound coming from inside your laptop — particularly during startup, file access, or when the device is moving — is the sound of a failing hard disk drive.

Traditional spinning hard drives (HDDs) use physical read/write heads that move across magnetic platters at extremely high speed. When the drive begins to fail, these heads can start to contact the platters — a condition called a head crash — producing the characteristic clicking or grinding sound known as the click of death. Once this process begins, drive failure can happen within hours, days, or weeks — but it will happen.

Solid state drives (SSDs) do not have moving parts and do not click or grind. If your laptop uses an SSD and you hear clicking sounds, the source is more likely the cooling fan — which is still worth investigating professionally, but is less immediately catastrophic than a failing HDD.

How to identify the source of the noise:

• Does the sound happen when the laptop is accessing files (saving, loading, copying)? → Almost certainly a failing HDD
• Does the sound happen when the fan speeds up (under load)? → More likely a failing or debris-obstructed fan
• Is it a continuous rhythmic clicking regardless of what the laptop is doing? → Classic HDD head failure — stop using immediately
• Is it a intermittent soft tick that comes and goes? → Could be thermal expansion (normal) or early-stage HDD issue — back up and monitor

Laptop batteries degrade naturally over time — it is an electrochemical process that cannot be avoided. A battery that was once capable of seven hours of use gradually deteriorates to six, then five, then three, until it becomes unusable without being permanently tethered to a charger. Most laptop batteries reach the end of their practical life after 500 to 800 full charge cycles — typically two to four years of regular use.

However, some battery problems are not about natural degradation. A battery that suddenly stops charging, swells visibly, or drains to zero within twenty minutes despite showing a higher percentage indicates a more serious problem that should not be ignored — particularly swelling, which presents a physical safety risk.

How to run a battery health report on Windows:

Battery problem types and what they mean:

• Battery drains faster than it used to: Normal degradation. A battery replacement (typically £40–£80) restores original battery life.
• Battery shows incorrect percentage (jumps from 40% to 5% suddenly): Calibration issue or battery cell failure. Try a full discharge and charge cycle. If it continues, battery replacement is needed.
• Laptop says "plugged in, not charging": Can be a driver issue (uninstall the battery driver in Device Manager and let Windows reinstall it), a faulty charger, a damaged charging port, or a battery that has completely failed.
• Battery is swollen or bulging: This is a safety issue. A swollen lithium battery risks rupture or fire. Stop using the laptop immediately, do not attempt to remove the battery yourself, and seek professional help urgently.

Screen problems in laptops fall into two distinct categories: those caused by software or drivers (which are fixable without professional help) and those caused by physical hardware damage or failure (which require professional repair). The way to distinguish between them is straightforward: if the problem appears on an external monitor connected to the laptop, it is a GPU or driver issue. If the external monitor is fine but the built-in screen has problems, it is a display hardware issue.

Types of screen problems and their likely causes:

• Flickering that comes and goes: Often caused by a loose display cable (the ribbon cable that connects the screen to the motherboard runs through the hinge and can loosen with repeated opening and closing). Also can be caused by an incompatible or outdated display driver.
• Horizontal or vertical lines across the screen: Usually indicates a failing display panel or a damaged display cable. If the lines are static and in the same position always, this is a dead column of pixels — panel failure. If they move or change, it may be a cable or GPU issue.
• Dead pixels (small black, white, or coloured dots that do not change): Dead pixels are almost always a panel defect. A single dead pixel is cosmetically annoying but functionally tolerable. A spreading cluster of dead pixels indicates the panel is beginning to fail.
• Screen goes black but laptop is still running (you can hear it and the external monitor works): Almost certainly the display backlight or backlight inverter (on older laptops) has failed.
• Cracked screen: Physical damage requiring panel replacement. Cost in 2026: typically £80–£200 depending on laptop model and panel type.

An occasional application crash is a normal part of using software — it happens. But when multiple different applications are crashing regularly, or when the operating system itself becomes unstable — programs refuse to open, the taskbar disappears, the system hangs at the login screen — this suggests a deeper problem than a simple buggy app.

Widespread instability across multiple different programs almost always points to one of three causes: failing RAM, a failing or corrupted storage drive, or a corrupted operating system installation. The first two are hardware problems; the third can sometimes be fixed with a Windows repair install.

Diagnosing the cause:

• Run Windows Memory Diagnostic: Search "Windows Memory Diagnostic" in the Start menu → Restart now and check for problems. This runs a comprehensive RAM test during startup. Any errors found confirm RAM failure.
• Run a storage health check: Download CrystalDiskInfo (free) and check the health status of your drive. Look for "Caution" or "Bad" status, reallocated sectors, or uncorrectable error counts above zero — all indicate a failing drive.
• Run the System File Checker: Open Command Prompt as administrator and type sfc /scannow — this checks for and repairs corrupted Windows system files, which can cause widespread instability.
• Check Event Viewer: The Application and System logs in Event Viewer often show the specific error that caused each crash, which can pinpoint the guilty component or driver.

Files do not disappear or become corrupted under normal operating conditions. If you are experiencing files that have vanished, documents that open as unreadable gibberish, saves that do not persist, or folders that appear empty despite containing files recently, this is a critical warning sign that demands immediate action.

There are two primary causes: a failing storage drive that is developing bad sectors (areas of the drive that can no longer reliably read or write data), or serious malware — particularly ransomware, which encrypts files and makes them inaccessible. Both are serious. Both require professional attention.

Signs pointing to drive failure:

• Files that opened yesterday now produce errors or appear empty
• Windows takes unusually long to read files or save documents
• CrystalDiskInfo (free drive health tool) shows reallocated sectors or uncorrectable errors
• CHKDSK reports bad sectors when run
• The problem is getting progressively worse over time

Signs pointing to malware / ransomware:

• Multiple files across multiple folders suddenly became inaccessible at the same time
• File extensions have changed to something unfamiliar (e.g., document.docx became document.docx.encrypted)
• A ransom note has appeared on screen or in affected folders
• The problem happened immediately after opening an email attachment or downloading a file

A laptop that refuses to start, or that randomly shuts down without warning mid-use, is exhibiting one of the most disruptive hardware symptoms possible. Unlike slow performance or screen flickering — which you can work around — a laptop that will not start or cannot stay on is essentially unusable. The cause can range from something as simple as a completely drained battery to something as serious as a failing motherboard.

If your laptop will not turn on at all:

If your laptop randomly shuts down mid-use:

• Overheating shutdown: Most laptops have a thermal protection that forces an immediate shutdown when temperatures reach a critical threshold. If shutdowns happen after the laptop has been running for 20–30 minutes and then it can be restarted immediately after cooling — overheating is almost certainly the cause. See Sign 1.
• Battery failure: A battery that reports a percentage but disconnects suddenly as if it hit zero is a failing battery cell. This causes abrupt, no-warning shutdowns.
• RAM failure: Failing RAM can cause sudden crashes and shutdowns without warning. Run Windows Memory Diagnostic to test this.
• Power circuit / motherboard: If none of the above match, a fault in the laptop's power regulation circuit or motherboard may be the cause — which requires professional diagnosis.

Individual hardware components in a laptop — keyboard keys, USB ports, headphone jacks, webcams, Wi-Fi cards, and Bluetooth modules — can fail independently of the rest of the system. These failures range from minor inconveniences that can be worked around (a faulty webcam when you have an external one) to serious usability blockers (multiple keyboard keys not working).

Common hardware component failures:

• Keyboard keys not working: First, try pressing firmly and checking for debris underneath (dust or crumbs under a key prevent contact). Use compressed air to clean under the key. If the key registers correctly on the Windows on-screen keyboard but not the physical key, the physical key mechanism or the keyboard ribbon cable is faulty — requires keyboard replacement.
• USB ports not recognising devices: First try the device in a different USB port on the same laptop. Try a different USB cable. Uninstall USB controllers in Device Manager (expand "Universal Serial Bus controllers" → right-click each USB Root Hub → Uninstall) and restart — Windows reinstalls them fresh. If a specific port still does not work after this, the port has physical damage or the USB controller on the motherboard is failing.
• Wi-Fi adapter not found or constantly dropping: Update the Wi-Fi driver via Device Manager. If the adapter disappears from Device Manager entirely, the Wi-Fi card may have physically failed — replaceable by a professional at relatively low cost.
• Webcam not detected: Check Device Manager for camera errors. Update the driver. If the camera does not appear at all, it may have physically failed or the cable connecting it has become loose inside the lid assembly.
• Charging port loose or intermittent: A charging port that only connects when the cable is held at a specific angle has a damaged connector. This is one of the most common physical repairs and should be addressed before the port fails completely — charging port replacement is typically £40–£80 but gets more expensive if the surrounding board is damaged from prolonged intermittent connection.

There comes a point where a laptop's slowness is not caused by bloated software, too many startup programs, or a need for a Windows refresh — it is caused by hardware that has reached its limits. A laptop running on 4GB of RAM in 2026, or on an ageing HDD with a first-generation CPU from 2015, is not going to perform well regardless of how cleanly its software is configured. The hardware is simply the bottleneck.

How do you know when you have crossed this line? If you have applied the ten software fixes from our previous guide — How to Speed Up a Slow Laptop Without Buying a New One — and the machine still feels painfully slow for basic tasks like email, browser work, and document editing, the problem is hardware-level.

The most common hardware bottlenecks in 2026:

• Insufficient RAM (4GB or less): Running Windows 10 or 11 with 4GB of RAM in 2026 means the system is constantly using slow disk-based virtual memory as overflow. Upgrading to 8GB or 16GB — where the laptop's motherboard supports it — transforms performance. Cost: £25–£60 for the RAM module.
• Traditional HDD instead of SSD: As covered in Sign 3, an HDD is orders of magnitude slower than an SSD. If your laptop still has a spinning hard drive and the budget for one upgrade, this is it. Cost: £40–£80 for the drive plus installation.
• An outdated CPU that cannot be upgraded: Unlike RAM and storage, the processor (CPU) in most modern laptops is soldered to the motherboard and cannot be replaced. A CPU from 2013–2016 simply cannot run modern software at a pace that feels responsive, regardless of how much RAM or how fast an SSD you pair with it. At this point, the honest answer is that the laptop has reached the end of its practical life.