Pattern to record: Windows Boot Manager or the expected loader is absent despite a healthy drive.

Record the boot configuration

Use the motherboard model and revision, not just the PC case brand, to select firmware documentation. Record POST indicators and recently changed memory, graphics or storage before returning settings to a documented baseline. One possible explanation is that the reference to a valid operating-system loader has been deleted or reordered.

Preserve recovery options

Firmware updates require the exact motherboard model and stable power. Selecting an unrelated entry may hide the real storage problem.

Firmware and hardware checks

1. Reduce to known hardware, inspect POST indications and compare saved settings with board documentation.
2. Verify the loader on disk and inspect the UEFI boot list.

Recovery and startup checks

If the checks support this cause, recreate the correct signed entry and place it in a sensible order. Verification should cover cold start, restart, memory training, storage, expansion cards and saved settings.

For an assessment of your desktop computer, contact AEPC in Burswood or call 027 908 8880. Provide the model and the conditions that reproduce this problem. Workshop visits are by appointment.