What does Windows error code 748 (ERROR_PAGE_FAULT_DEMAND_ZERO) mean?

ERROR_PAGE_FAULT_DEMAND_ZERO

A demand-zero page fault allocated a newly zeroed page

ERROR_PAGE_FAULT_DEMAND_ZERO corresponds to Win32 error value documented as: Page fault was a demand zero fault. The virtual address belonged to committed memory with no previous backing data, so Windows supplied a zero-filled physical page on first access. This is expected behavior for many allocations.

Where the result appears in real systems

• First touch of VirtualAlloc memory.
• Stack growth.
• Heap expansion.
• Memory-profiler and kernel trace events.

What to collect before making changes

Record the allocation origin, address range, access pattern, commit charge, and system memory pressure; compare the rate with expected initialization rather than counting every event as an error.

Handling and recovery

Usually accept the event. Optimize only when first-touch latency or large bursts matter, for example by touching pages deliberately on a suitable thread or reducing unnecessary committed memory.

What not to infer from this code

This result is not data loss and does not indicate a zeroed file. It describes how anonymous committed memory receives its initial contents.

References

• Microsoft: System error codes 500–999