failed to find an appropriate PIXELFORMAT
…restoring display settings
…WARNING: could not set the given mode (3)
…shutting down QGL
…unloading OpenGL DLL
GLW_StartOpenGL() - could not load OpenGL subsystem

HELP!!! what is pixelformat?

The pixel format is a set of numbers that describe the graphics buffers OpenGL will use.
For example, RGBA, 8 bit per component and stencil = 8 bit, depth buffer = 24 bit.
That’s one pixelformat that the graphics device may or may not support.