Windows 10 can and will directly modify UEFI configs and files. Windows 10 cannot directly alter BIOS firmware.

Can Windows 10 update my BIOS?

How do I update my BIOS in Windows 10? The easiest way to update your BIOS is directly from its settings. Before you start the process, check your BIOS version and the model of your motherboard. Another way to update it is to create a DOS USB drive or use a Windows-based program.

Can Windows affect BIOS?

The BIOS is unrelated to Windows and Windows updates will no ways affect it. BIOS updates are provided by the motherboard manufacturer.