Just in case someone else had the same problem:
After installing the “hot fix” for Cubase LE 4, updating it to version 4.13 on a Win 7 64 bit system, I had problems such as no more Halion accessible. After de-installing to start all over, it was murder to re-install, hung up several times. Finally, by pulling the installation window to one side, I saw a notice that running processes were disturbing the installation and I should re-start. That led to a repeat, so I finally just clicked the notice away, and lo and behold, LE 4 installed and functioned.
The upgrade before the hot fix, version 4.12, installed successfully without the issues of the hot fix. I’m not going to try the hot fix again.
Apparently I don’t have to go through the registration treadmill again, the program started normally and seems to be a stable version.