If it won't be a silly question how can I reinstall? Because I tried to format with usb, umount device from xfe, install another linux system and install tiny core again, but always when I try to TC_install, always same error : "sda appears to have a partition already mounted! Check if correct device, if so, umount it and then run installer again." and when I restart computer version is 6.4. ( Usb format is update version but after restart computer version is again 6.4)