HTMLPrint will use GDIPLUS.DLL for displaying PNG images. This will allow proper rendering of PNG images with Alpha transparency.
If GDIPLUS.DLL is not present, PNG images will still be displayed but without the Alpha transparency capability.
By default GDIPLUS.DLL will be installed in HTMLPrint directory. In case you remove the DLL file from HTMLPrint directory, HTMLPrint will continue working, but without the Alpha transparency capability for PNG images.
If there is another GDIPLUS.DLL file in the System search path, the one that gets loaded before is the one that will be used, no matter where it is located.
In all cases, if the GDIPLUS.DLL file in HTMLPrint directory is removed, the DLL will not be used afterwards by HTMLPrint, no matter if it is loaded by other program in other location.