win32k.sys

Full/Desktop Multi-User Win32 Driver: the kernel mode part of the Windowing subsystem GUI.

win32k.sys hosts the following functionality:

• Window manager
• GDI
• Wrappers for DirectX that are implemented in dxgkrnl.sys

Depending on the Windows edition(?), Win32k.sys loads win32kbase.sys and win32kfull.sys