CLOCK_WATCHDOG_TIMEOUT: what causes it and how to fix it
Every core of a processor answers a regular timer. CLOCK_WATCHDOG_TIMEOUT, stop code 0x101, means one core stopped answering: in Microsoft’s words, it is not processing interrupts, typically because it is unresponsive or deadlocked. On a home PC that nearly always points at the processor’s stability rather than at a program.
Updated 10 November 2026
The usual causes
- An overclock or undervolt. The classic cause: a core given too little voltage for the speed it is asked to run at stops responding under load. That includes AMD’s Curve Optimizer set too far negative and motherboard settings that push the processor beyond its own limits.
- An old BIOS. Processor microcode and power management fixes come in BIOS updates, and a newer processor in an older board may need one.
- Intel 13th and 14th gen desktop processors without Intel’s microcode fix: their instability can show up as this code among others — how to check yours.
- Heat, from a cooler that is badly seated or clogged.
- A memory profile (XMP or EXPO) set too fast, less often.
How to fix it
- Update the BIOS to the newest version for your motherboard that is not marked beta.
- Go back to defaults. Load the BIOS defaults, or switch off every overclock and undervolt — on AMD, Precision Boost Overdrive and Curve Optimizer; on Intel, any undervolt, and choose the Intel Default Settings profile if the BIOS offers one.
- Test under load. An unstable processor usually fails a stress test within minutes. Watch the temperatures while it runs.
- On a 13th or 14th gen Intel processor, install the microcode fix. If it still fails afterwards, the processor may already be worn — the fix stops the wear but cannot undo it — and Intel extended the warranty on these processors by two years.
- If it still crashes at defaults, install the newest chipset driver, then suspect the processor or the motherboard.