I discussed update and upgrade scenarios by email with IDM during beta testing as 3 main use cases must be taken into account when updating/upgrading from a version of UltraEdit < 22.20 to version 22.20 (or in future a later version).

1. UltraEdit < v22.20 is installed with a definitely different installer than UE v22.20 (or later) uses.
   This means an incremental update/upgrade is not possible at all. Either the user or the new installer needs to run first an uninstall of already installed UltraEdit to get rid off the files and registry keys of the old installer not used further in future.
2. Installed is currently the 32-bit version of UltraEdit, but installer of 64-bit version is started now as the user wants to replace the older 32-bit by the latest 64-bit version.
3. A user wants to use 32-bit AND 64-bit version of UltraEdit on same machine.

The installer of UE v22.20 first always checks if UltraEdit is installed already and which version is installed respectively with which installer the existing UltraEdit was installed. In case of detecting that existing UltraEdit was installed with a previous installer, it automatically runs the uninstaller of the already installed UltraEdit to delete all program files of UltraEdit and the files of the previous installer. The configuration files remain as the installers prior UE v22.20 do not even support removing application data, just removing the program files. This is done independent on running 32-bit or 64-bit installer of UE v22.20. So use case 1 and 2 are managed by the installer of UE v22.20.

The uninstall of UE < 22.20 is necessary in any case not just because of old installer removal, or upgrading from 32-bit to 64-bit version, but also because of different structure and file names in program files folder of UltraEdit.

However, it is always safe to first uninstall UltraEdit, restart Windows in case of shell extension DLL was used which can't be deleted immediately by the uninstaller as being loaded by Windows Explorer, and then install new version of UltraEdit. I do this for every application at least on every upgrade, i.e. first number in version (major version) changes. It is always good to uninstall an application from time to time when having made already several incremental updates. Uninstalling an application does not mean to get lost the application data, i.e. the users configuration for the application. All installers leave the application data on disk respectively in registry on uninstall, except the uninstaller has a special option to remove also the application data like new uninstaller of UltraEdit has. But this special uninstaller option must be always manually checked by the user. I have never seen an uninstaller offering an option to remove also application data with being checked by default.

On first start of uedit64.exe v22.20.0.25, the configuration files in %APPDATA%\IDMComp\UltraEdit from a previous uedit32 installation are taken over. So for most users the entire user configuration is kept after an upgrade from 32-bit UE < v22.20 to 64-bit UE v22.20.

But some configurations were overlooked like having stored the user configuration in Windows registry instead of files as by default, or the file associations made with UltraEdit with previous 32-bit version of UltraEdit not being updated automatically to 64-bit version of UE on first start of uedit64.exe, see this post by forum member Everyone.

I'm quite sure that a hotfix version of UE v22.20 or UE v23.00 at the latest will take care also about registry values and registry keys which need to be modified by uedit64.exe on first start after upgrade when all users detecting such an issue report it also by email to IDM support so that IDM Computer Solutions are aware of those migration issue.

Installing both, 32-bit and 64-bit version is possible into different directories, but currently NOT recommended because UltraEdit is not designed for a dual installation of both versions. For example uedit64.exe uses uedit64.ini and uedit32.exe uses uedit32.ini. This is not really useful for a user using both versions of UE at the same time as it can be expected that no users wants to make changes in configuration twice or have different histories for each version of UE. I think, there is also a problem with FTP/SFTP/Telnet/SSH registration when having both versions of UE installed on a machine.

Let's see if there will be enough users really wanting support for dual UltraEdit installation and appropriate data and DLL management, and if IDM Computer Solutions make appropriate adaptations for 32+64 bit installations like my favorite file manager Total Commander supports. In my estimation there will be only a few users who want both versions installed on same machine for same user (in same program files directory). I would like it, but only for making forum support easier for me in future on answering forum questions related to 32-bit or 64-bit version, not for my personal usage. I have currently just 32-bit version of UE v22.20 installed on my Windows 7 x64 computer.