To install a program, in the folder of another, especially from Program Files, you need to run the installer using Administrator rights. This is the reason why you encounter the protected memory error. To run a program with administrator rights, just right click on its EXE file and choose Run as administrator.
There is no information over the Internet about the installation process of the DICOM Importer. If you still can't use it, the best thing that you can do is to contact the developer on its official website. This way you can obtain additional information about the use ofthe program and its installation process.