Did not know exactly where to put this request so here goes. I am using a VFP addon product that requires MSVCRT.DLL. I thought that since there are MSVCRT20 and MSVCRT40 on various machines that obviously MS was naming this according to the version that it was to support so I would be safe installing it on all machines. I have just recently discovered that there are many versions ( different file sizes and different dates) of this file. Is this a file that is used by the system? Have I descended into DLL hell? Am I causing my customers machines to crash in other programs? Any advise or help will be greatly appreciated.