Looks like this has come up in 2017 and 2020, but there doesn’t seem to be a solution so far.
I just updated to 3.27.1, which properly removed the 3.26.x version, but the older versions still appear. Is this just an issue of registry entries not being updated, or are there still old files remaining that could/should be cleared out? Remove Programs has the Modify and Uninstall options greyed-out.
Thanks for reaching out about this! The older entries of PreForm you noticed are indeed old registry entries which were not updated. This issue has since been fixed, as you saw when updating to version 3.27.1. These duplicate entries are harmless and do not correspond to old files remaining. With that said, if you would still like to remove these entries, you would need to do a registry edit. For complete instructions on this process, please reach out to our Support Team - extra caution would be prudent in this case to avoid improper registry edits.