Could you change the installer to support uninstalling previous versions
The Inno Setup compiler that I am using does not support uninstall when installing a new version.
or change the installer to install into the same folder.
If you have made custom scripts then you will want a copy of the MyDefrag program for which you developed the script. If you don't like the default installation directory then simply change it (you can select it when installing).
When you remove one of the installed versions the file associate is also removed ..
Yes, will be fixed in the next version.
Installing an older version also overwrites a newer version of the screensaver.
Sorry, can't be helped. The last installed version is the active version.