all files changed from read & write to read only without my permission

Solution 1:

Your disk is probably in read-only mode due to file system errors.

  • boot to a Ubuntu Live DVD/USB in “Try Ubuntu” mode
  • open a terminal window by pressing Ctrl+Alt+T
  • type sudo fdisk -l
  • identify the /dev/sdXX device name for your "Linux Filesystem"
  • type sudo fsck -f /dev/sdXX, replacing sdXX with the number you found earlier
  • repeat the fsck command if there were errors
  • type reboot