I have uninstalled the old XAMPP and deleted all of the content of d:\\xampp folder
and installed the new one. When I copy my backup folder (with the name of my
I've searched a lot. There's a few other files that are needed for recovery. I think it's impossible to recover tables from the .frm files alone. I've re-created my database.
I have found a solution for this. I Installed new XAMPP and Replace old bin folder in Apache and mysql folders in old XAMPP with new folders from newly Installed Xampp I have recoverd all my data.
I found this searching for the way to recover my XAMPP databases in Ubuntu. The question is obviously for a Windows system, but I think this might be of help since this was the only good search result.
For a standard installation in /opt/lampp/. You can recover the databases from the folder /opt/lampp/var/mysql/ if you have a backup of the whole lampp installation. (You might consider to add the mysql folder to your backup system, if you haven't.)
Your old databases should be accessible again.