I have a no-name Celeron N3450 laptop with an HD Graphics 500 integrated graphics card and a no-name, knock-off motherboard BIOS. The SeaVGABIOS provided by CSMWrap worked amazingly. I could switch boot devices using ESC, and even USB 3.0 flash drives were recognized! However, things didn't go smoothly. I subsequently ran Windows 11 PE and then Windows 2003 PE, and both resulted in ACPI-related BSoDs (ACPI_BIOS_ERROR and 0x000000A5). Some versions of DOS would display a "Divide Error," while others worked fine.

I then installed Windows 7, and it still had the A5 BSoD. However, it's a bit strange that CSMWrap only passes the UEFI ACPI table directly to the legacy environment. I tried installing Windows 7 purely using UEFI, but I couldn't get the HD 500 graphics driver to work properly under Win7. It got stuck at the boot animation, but everything else worked perfectly! I even heard the Windows 7 startup sound. I blindly typed shutdown /s /t 000, and the computer played the shutdown sound followed by a black screen. At least this shows that Windows 7 is working properly, but the HD 500 driver isn't working, causing the startup animation to get stuck.

So if CSMWrap can pass through ACPI directly, the A5 BSoD shouldn't occur. Any way to fix it, please?

I hope your project continues to improve!