Moving jAlbum to a new PC
Here's a summary of what you need to do to move jAlbum from one PC to a new PC. These instructions apply primarily to Windows, but the instructions for macOS are virtually the same.
Copy your original image files from the Pictures folder on the old PC to the Pictures folder on the new PC. If you've been keeping your image files somewhere else, you need to copy them to a similar location on the new PC.
Install jAlbum on the new PC, as well as whatever non-bundled skins you want. Now copy your existing jAlbum projects over to the new PC. On the old PC, choose Tools, Preferences, Album, "My albums location". Using File Explorer (sometimes called Windows Explorer, and Finder on a Mac) go to that location, and there should be a subdirectory (folder) for each of your projects. Copy each of those folders to the MyAlbums folder on your new PC - its exact location, which may be different from your old PC, can be found on the new PC by choosing Tools, Preferences, Album, "My albums location".
Your default settings (for creating new projects) and web hosting account settings are stored in defaults.jap and accounts.xml. From within jAlbum on the old machine, choose Tools, Open directories, Config directory to locate those files. Copy them to the config directory on the new machine.
If you're changing operating system versions, you may have to fix some path names, since things are kept in different places. You can run into similar issues if you're changing your name on the new PC. This is particularly true if you had jAlbum set to keep only links to the original image files, rather than copying them into the album project (the default).
If you open an album project on the new PC and instead of seeing a thumbnail you're seeing a red "X," that means that the original images are no longer where jAlbum expects them to be. Double-click on the first missing thumbnail, and navigate to where the image files are now stored, and select the correct image file. jAlbum will attempt to correct the other path names based upon this one, but you may have to repeat this procedure for other missing images.
If, for a given album project, you have changed the Output directory to something other than its default location - an album directory within the project directory - you'll have to handle that manually. Copy the finished album from wherever you stored it on the old PC to wherever you plan to store it on the new PC, then correct the path under Album > Settings > General > Output directory.
If you encounter problems, start a thread in the General Discussion section. Be sure to tell us which version of Windows is on the old and new PC's.