What you want to ask is what to do if the digital signature is lost after changing the bios graphics card driver? Update the driver software.

In the right-click menu of the computer, select Manage to enter computer management, and click Device Manager. Locate the graphics adapter used by the display adapter and right-click to update the driver software.

Digital signature (also known as public key digital signature and electronic signature) is an ordinary physical signature, similar to the signature written on paper, but it is realized by using the technology in the field of public key encryption, which is used to identify digital information.