coreboot

Please mention the exact coreboot version, and payload with version.

Also, please transcribe the BSOD messages (error codes).

Sorry for the wait I got the error codes from the bluescreen here:
ACPI_BIOS_ERROR

0x00001000
0x00000000
0x00000000
0x00002000

According to a statement on the old wiki:
Parameter1 == 0x00001000 means that some memory resource is claimed by ACPI that, according to memory tables, belongs to the OS. Parameter3 is the start address, Parameter4 is the length of the range. They can probably be found somewhere in the ASL code.

I ran into this bug as far back as the initial 8770w workstation commit @ 8a2b7f31fb28b35c6a3ffa1c01dd1c26bc925638 when I first tried an HP build, it appears to happen with both Tianocore & SeaBIOS, grub has a separate freezing issue with hp notebooks, version I'm using is git master.

I don't know about Windows 7 because I've never successfully booted it on hardware running coreboot. But Windows 8.1 is fine when using SeaBIOS (with VGA BIOS) and Tianocore (using libgfxinit) payload on my 2560p when I try to use Windows on this laptop these two days.
However, I've found some ACPI issues. Windows shutdown cannot power down the machine, and Windows says no batteries are connected.
8770w may be another story because it has a discrete graphics card.