I forgot my ubuntu autheticate password!

Question

I was trying to download GIMP on my computer,it asked for a autheticate password! of course I didn't know it,so I wasn't going to try to type it in if it was only going to say it was wrong What should I do?

Answer 1

Reboot your system and select Advanced options from Grub. Then select Ubuntu (recovery mode) and change password for existing user:

1. Run

   passwd user_name
   

   Replace user_name with your actual username.

2. Type password when prompt:

   Enter new UNIX password:
   

3. Retype password (it will ask so).

4. Reboot and use your new password.