A blue screen is Windows stopping deliberately because continuing would risk your data.
It’s frightening but it’s diagnostic — and the message on screen tells you more than most
people realise.

Write down the stop code

At the bottom of the blue screen is a line like SYSTEM_SERVICE_EXCEPTION or
CRITICAL_PROCESS_DIED. That is the single most useful piece of information, and
it’s the thing everyone forgets to note before restarting. Photograph the screen with your
phone.

What the common ones usually mean

• DRIVER_IRQL_NOT_LESS_OR_EQUAL — almost always a driver, and the screen
  often names the file. Graphics and network drivers are the usual suspects.
• MEMORY_MANAGEMENT — frequently genuine faulty RAM, though it can also be
  a driver. Worth running the memory test below.
• CRITICAL_PROCESS_DIED — a core Windows process failed, often after a
  half-finished update or from corrupted system files.
• INACCESSIBLE_BOOT_DEVICE — Windows can’t reach the drive it boots from.
  Sometimes a storage driver, sometimes a failing drive.
• WHEA_UNCORRECTABLE_ERROR — the hardware itself reported a fault. Often
  overheating, sometimes a failing component.

Ask the obvious question first

What changed? New hardware, a new peripheral, a Windows update, or a driver update in the
last few days is the cause far more often than anything mysterious. If the blue screens
started the day after something changed, reverse that thing first.

Three checks worth running

Memory test

Search for “Windows Memory Diagnostic” and let it run on restart. It takes a while and
it’s worth it — faulty RAM produces random, unrelated-looking crashes that send people
chasing software problems for weeks.

System file check

Open Command Prompt as administrator and run sfc /scannow. If it reports
problems it couldn’t fix, follow with
DISM /Online /Cleanup-Image /RestoreHealth and then run the first command again.

Check the temperatures

If the machine crashes under load — gaming, video, large exports — and is fine when idle,
suspect heat. Desktops full of dust and laptops used on soft surfaces both throttle and then
fault. A can of compressed air is sometimes the entire fix.

If it crashes before Windows loads

Hold Shift while clicking Restart to reach the recovery options, and try Safe Mode. If the
machine is stable in Safe Mode, the problem is almost certainly a driver or a startup program
rather than the hardware — which is good news, because that’s much easier to fix.

The part people skip

Before troubleshooting further, get your files off the machine. If the cause turns out to
be a failing drive, every extra hour of use reduces what can be recovered. Copy what matters
to an external drive or cloud storage first, then diagnose.

If you’d rather someone worked through it properly — including checking whether the drive
is on its way out — that’s what we do in Adelaide. Call 08 7094 4824.