For backup you only need embedded-db, conf and if you use SSL, resources\security folder. As you are using old Openfire, you should also copy plugins folder. As you won't be able to redownload plugins. That's the problem with Users import export. You won't find older plugin version, which will work with 3.7.0.
Installing 3.7.0 on Windows 7 and dropping backup on top should work. I have probably mentioned this, but if you plan to launch Openfire via launcher (maybe for the first time, before installing the service) on Windows 7, you MUST do it via Run as administrator command, or it will show a lot of red errors and won't work.