0x000001D9 is a hardware-reporting stop code result. It indicates that an internal error was detected in the HAL IOMMU library.
Code reference and safe checks
Read the exact screen and operation before selecting a repair. This page does not run commands or collect files, keys or logs.
What this value means
It indicates that an internal error was detected in the HAL IOMMU library.
HAL_IOMMU_INTERNAL_ERROR identifies a stop-code family. The four bug-check parameters and dump, if available, help distinguish the actual failure path.
| Code | 0x000001D9 |
|---|---|
| Short hex form | 0x1D9 |
| Symbol | HAL_IOMMU_INTERNAL_ERROR |
| Windows family | Blue screen and stop codes |
| Source level | Microsoft bug-check page |
Microsoft’s technical cause notes add: An internal error was detected in the HAL IOMMU library.
The linked debugger page also describes its parameters: Failed Operation Values
Safe next steps
- For 0x000001D9 (HAL_IOMMU_INTERNAL_ERROR), record the stop code, parameters and any hardware error record or OEM diagnostic result.
- Check the exact PC maker’s hardware, thermal and firmware guidance before changing components. The bug-check name alone cannot identify a replaceable part.
- Stop repeated high-load testing if the device overheats, powers off or cannot preserve important files.
After one step, repeat the original operation and record whether this same code returns. A different code needs a fresh interpretation.
What this code cannot prove
The source establishes the identifier and reference meaning. It does not establish the cause on your specific PC.
If Windows no longer starts or the issue repeats with hardware warnings, protect files and use manufacturer or qualified support.
Official reference and verification
Source type: Microsoft bug-check page. Checked against the source set on Nov 2, 2026.
The reference gives the meaning of this identifier. It does not inspect your PC or guarantee that one repair will work.