Blue Screen (BSOD) Error:
Causes and Solution

First answer this question: when did it start?

The quickest route to a diagnosis is to look at the moment the fault began. This single question eliminates half of the possible causes:

Read the error code — the real information is there

On the blue screen there is usually a sad face, a percentage indicator and at the bottom you will find stop code . That code is not a guess but a direct clue given to you by the system. The most frequent ones and what they mean in practice:

• MEMORY_MANAGEMENT — An inconsistency in memory management. The first suspect is the RAM, but a faulty driver can produce the same code as well.
• IRQL_NOT_LESS_OR_EQUAL — A driver accessed a memory area that it should not have. This is predominantly caused by drivers.
• PAGE_FAULT_IN_NONPAGED_AREA — The expected data could not be found in memory. RAM or disk.
• CRITICAL_PROCESS_DIED — A process that is essential for Windows to run has terminated. Usually corrupted system files.
• INACCESSIBLE_BOOT_DEVICE — The system disk cannot be read. A disk fault, a loose cable connection or a changed disk mode in the BIOS.
• WHEA_UNCORRECTABLE_ERROR — An error that cannot be corrected at hardware level. The processor, the motherboard or the power supply is examined. If overclocking has been applied, the first step is to undo it.
• VIDEO_TDR_FAILURE — The graphics card driver did not respond. Either the driver or an overheating/worn graphics card.

If the code is different appears, that too is information: varying codes usually point to a component that affects the system as a whole, such as the RAM or the power supply. If the code is always the same every time, the range of possible causes has narrowed.

1. Undo the most recent change

If the fault began after a particular event, the solution lies there as well. Remove the part you have just fitted and test again; roll the updated driver back to its previous version through Device Manager. For blue screens that begin immediately after a Windows update, removing the update usually corrects the situation straight away.

On a system that has been overclocked, the first step is always to reset the BIOS settings to their defaults. Memory kits that run unstably while the XMP/EXPO profile is enabled produce exactly this picture.

2. Test the RAM

Memory errors are the most classic cause of the blue screen and testing them is free of charge. Windows' own Memory Diagnostics tool gives an initial indication; however, we frequently encounter modules that look clean in a short scan but fail in a long test. For this reason we apply long-duration testing in our service centre.

If there is more than one module, try them one by one

This is the most reliable and cost-free method: fitting the modules one by one and using the device. If the error occurs only with a particular module, the culprit has been found. If the error persists even when you change the modules over, the motherboard slot then falls under suspicion.

Oxidation of the contacts is also a more frequent cause than assumed. Removing the module and reseating it firmly in its slot can on its own solve the problem, particularly in desktop computers that have not been opened for a long time. If you are considering a memory upgrade, the compatibility criteria in our RAM upgrade guide we explained in detail.

3. Check the disk

A drive nearing the end of its life produces not only blue screens but also freezes and start-up problems. The drive’s own health data (S.M.A.R.T.) speaks quite plainly on this point: if the reallocated sector count is rising, the drive is warning you.

• In an administrator command prompt chkdsk /f /r repairs file system errors.
• sfc /scannow restores corrupted Windows system files.
• If you hear a clicking or a cyclical noise from a mechanical disk, do not run any tests; stop using the disk.

The reason for the last point is this: every read attempt on a faulty mechanical disk reduces the amount of recoverable data. At that stage the correct move is to switch the device off. For details, see our data recovery guide should be consulted.

4. Measure the heat build-up

For blue screens that appear only under load, overheating is a strong candidate. When processor and graphics card temperatures reach the critical threshold, the system first reduces its speed and then stops in order to protect itself. Dust build-up and dried-out thermal paste are the two main causes of this; in our overheating guide we set out in detail.

5. Install the drivers cleanly

With graphics card drivers in particular, installing “on top” leaves residue and creates conflicts. The correct method is to remove the existing driver completely and carry out a clean installation of the current version downloaded from the manufacturer’s website. Download the driver from the manufacturer’s own page; third-party “driver updater” programs frequently turn out to be the source of the problem at our service centre.

6. Rule out software with a clean boot

The way to find out whether a program running in the background is causing a conflict is to start the system with Microsoft services only. If the error disappears in that case, the cause is one of the installed applications and can be narrowed down by enabling them one at a time. Several antivirus programs being installed on top of one another is also a frequent cause in this group.

When should it be brought in for service?

If the steps above have produced no result, or if the error code points to a hardware-level problem such as WHEA, measuring instruments and spare parts are required for diagnosis. Instability in the power stages on the mainboard or in the power supply cannot be detected with software.

At our service centre in Çankaya, in the case of blue screen complaints we first examine the system logs and the dump files, and then verify the memory, the drive and the power supply separately with our own test hardware. In this way no sound part is replaced, and the work is carried out where the fault actually is.