0x000000A5
ACPI_BIOS_ERROR
What it means
The firmware handed Windows ACPI tables it cannot use, so the machine stops while it is still reading the hardware description.
Common causes
- A BIOS that is far behind the installed Windows version
- A laptop model with incomplete ACPI support
- A CMOS setting changed by an overclock utility
How to fix it
- Load the BIOS defaults, save and retry.
- Update firmware only from the maker's official support page, with the PC on a stable power source and nothing else running.
- If it only happens on one Windows build, roll that build back and check the vendor's support page for a fix.