Warning
Create a Time Machine backup before major updates, disk operations, or security changes on macOS.
What you will achieve
When macOS sits on “Installing” for hours, try these steps before forcing power off.
1) Wait for genuine stall threshold
If progress has not moved for over 2 hours and disk activity is near zero, treat as stuck.
2) Free space and retry
- Boot normally or Safe Mode and free at least 30 GB.
- Retry from System Settings → General → Software Update.
3) Use Recovery if repeated failures occur
- Boot into Recovery and run Disk Utility First Aid.
- Choose Reinstall macOS without erasing data first.