Yes. It means you ran Reforged World Editor on the computer previously, and Reforged World Editor modifies the registry so that the older versions will no longer run.
You can revert the effects of this by deleting a registry key called Tool Windows. I only know this courtesy of one of the former Reforged developers who no longer works at Blizzard, who kindly told me what registry key to delete, so big thanks to the former Reforged devs on discord for this one.
The registry key to delete I believe is Computer\HKEY_CURRENT_USER\Software\Blizzard Entertainment\WorldEdit\Tool Windows
. I am writing this from memory while sitting in an armchair, so definitely be careful in the registry editor and only and specifically press delete on the key named Tool Windows and don't delete anything else.
But yeah I delete that key probably two to five times per week, as I continue to be a power user of both versions of the World Editor. So, it's not like some weird problem with your disk, this is deterministically how these programs interact on all PCs.