Dear,
Thank you for reply.
I have not reinstalled xampp again. But yeah, before installing the windows operating system, I copied the whole long time ago Installed folder of C:\xampp to the External HDD, than did windows reinstallation and after all that, I copied back the xampp folder from External HDD to C: now, and tried opening the site, the changes I made with so much effort are gone, everything set to Normal. The old mysql data in phpmyadmin has not been changed at all, it is still the same, but I can’t see any page or post I created after windows reinstallation or moving of xampp in c: drive.