IDL Version: 7.1 Compiler: Microsoft Visual Studio 2008 Platform: Microsoft Windows XP-64 I have created a project in IDL which uses a custom DLL/DLM (release x64) that I created and compiled using Microsoft Visual Studio 2008. The DLL compiles fine and when I add the DLL and DLM to the IDL DLM Path the program works fine within the workbench and in a stand alone Run Time Distribution created from Make_RT on a machine with Visual Studio and a full IDL license installed. The problem lies when I try to run the Make_RT /VM runtime on a machine without IDL or Visual Studio. When I run the program and it hits a line which needs to load my custom DLL/DLM it brings up this Error in an Error Window: Here is the Error - IDLtoC.dll is my custom dll - CustomFunc is my function within the .dll - CustomIDLRoutines is my .pro file that calls the CustomFunc *****ERROR********* Error trace: % CustomFunc: Error loading sharable executable: Symbol: IDL_Load, File = D:\Tools\IDLtoC.dll The specified module could not be found. % Execution halted at: CustomIDLRoutines % WR_DEMHDR_TXT % ONPRESS_INFO % WID_TLD_DV_EVENT % IDLRTMAIN % $MAIN$ *****END OF ERROR**** - I have ensured that the Visual Studio 2008 x64 run time distributable had been installed - I have also ran IDL71\bin\make_rt\systemdll64_setup.exe on the machine without IDL and visual studio and this ran without error - It is strange to me that the MAKE_RT /VM program works fine when a system has IDL and Visual Studio but when it has neither it balks and gives me the error on my custom DLL's. - Do the .dll's need to be compiled differently with visual studio to allow the ability to be used on machines without visual studio? - Do I need to add any special files to my IDL Run Time project folder? Maybe a specific visual studio dll? Thanks.