#su - # #Suppose Set user sampleusername to administrator #usermod sampleusername -a -G root

Or directly add below line into /etc/sudoers file:

sampleusername ALL=(ALL) ALL

During Installing Fedora 20 via DVD ROM, Error “you have not created a bootloader stage1 target device” :

Solution: Reboot the computer and go to boot menu(priority) in BIOS setting. Select normal DVD Room boot up instead of EFI: DVD Rom.