So I had a perfectly rooted Galaxy Y w/ Android 2.3.6, but then I can't remember why, but I changed in some system files and my device is no longer rooted. I've tried everything but nothing resets all system files. Is there any way I can reset everything, like all system file?
This may wipe all user data!!!
So make a backup just in case!!!!
You need to flash your appropriate firmware package of your device, download it here:
Download Odin (google it) Open Odin (duh)
Reboot your phone to download mode.(google it if you don't know how to)
Connect your phone to the computer
Put the firmware package in
Klik start to begin and your phone will reboot with "new system files"
Hope my answer helped.