1- Save any pending transcriptions, right-click them and select "Save as DCT".
2- Uninstall Express Scribe. Then, delete a folder called "Scribe" from these locations:
- C:\Program Files (x86)\NCH Software\
- C:\ProgramData\NCH Software\
- C:\Users\<your username>\AppData\Roaming\NCH Software\
(if you can't find the ProgramData or AppData folders, set Windows to show hidden files and folders as per https://support.microsoft.com/en-us/help/14201/windows-show-hidden-files)
3- Restart the PC. Then, download and reinstall Express Scribe using the software version covered by your license, and enter your registration code.