FineReader 14 and FineReader 15 are installed on a computer as two different programs.
After upgrading to FineReader 15 you also receive upgraded Screenshot Reader and Hotfolder. All Hotfolder tasks need to be exported from FineReader 14 and imported to FineReader 15 before the old version of the program is deleted.
You can delete the old version of the program after you have saved all Hotfolder tasks, unfinished PDFs and FineReader 14 projects.
After opening a FineReader 14 project in FineReader 15 you will be offered to re-save the project so you could continue working on it in the new version. Your progress will be saved.