Hi Andrew ,
From Windows side you can try follow the step below:
1/ Create installation media and plug on device -> https://www.microsoft.com/en-gb/software-downlo...
2/ Select Command Prompt and type the following commands, then press Enter:
Bootrec / fixmbr
Bootrec / fixboot
Bootrec /rebuildbcd
3/ Close the Command Prompt window, then restart your device.
Let me know how this goes
Bootrec /FixMbr completed successfully.
Bootrec /FixBoot came back with "access is denied".
Bootrec /Rebuildbcd found 0 Windows installations.
No joy.