As with other dynamic-link libraries, Windows calls the grabber's initialization routine, InitGrabber, when it first loads the grabber. InitGrabber can carry out any initializations the grabber needs. However, most grabbers wait until WINOLDAP calls the CheckGRBVersion and GetFontList functions to carry out initializations.
WINOLDAP calls CheckGRBVersion to check the grabber's version number and to let the grabber make sure the virtual-display device is compatible with the grabber. It calls GetFontList to retrieve a list of fonts for drawing text in a window.