Search for 'SE2DDraft*.*' without the quotes. The full filename is SE2DDraftV104ENGLISH.exe.
If you downloaded another language, 'ENGLISH' in the filename will change to the language downloaded. This is an installation executable. You run this executable to install the software. If you still cannot find the file go back to the web site and register again and download the file again. If you do not save the file, it will put it in a temporary folder. If you save it you can specify where it is saved and then run the saved executable.
I prefer saving the executable. This way I have it if I need to reinstall the software.
I can assure you that the software works. We have 300000 downloads and installations of the software working with no issues.
Ensure that you have the UAC disabled when installing. Install as an administrator.