Add your BMP files as resources (#AutoIt3Wrapper_Res_File_Add=image1.bmp, rt_bitmap, TEST_BMP_1) and use RecourcesEx UDF (link in my signature) --> _Resource_SetToCtrlID() This will fix flicker problem and minimize (WM_PAINT) problem too and your code in your script will be very simple and you will not need FileInstall() BMPs to TEMP directory.