Good idea, i also thought about this but i have no installer for the previous version (i don´t keep the installers or .zip files because until now that would be over 1 TB)
I’ve learned the hard way to keep the last three or four versions of DS saved back. The alternative is to try manually uninstalling DS, but that means hunting down every directory and file and deleting them yourself, maybe doing a regEdit to erase every entry—it can be done, but it’s a pain.
When you install the new version, doesn’t it give you the option to delete the previous version or to continue with the install? I don’t usually install DS on top of itself, so I wouldn’t know. I usually try to clean the previous version off first before installing a newer version.