Unfortunately you can’t just take some files or folders from a database and move them to another one.
But you can move the whole eM Client appdata folder you saved from the old Windows to the same location on the new Windows and then start eM Client. By default the database is the complete C:\Users\yourusername\AppData\Roaming\eM Client\ folder. You may have to enable hidden items in Explorer to get there.
Otherwise, if you have a recent eM Client backup, use Menu > File > Restore to restore it.
Thanks for the quick reply.
I had already read the suggested solution, but I still have to install the database.
So I copied it over from the folders.
Unfortunately, I didn’t think about the backup until later. could save it in a cloud on onedrive. but now it’s happened