Bootable DVD doesn't load up windows setup

MartianGeneral

Honorable
Dec 17, 2012
29
0
10,530
Hello, I want to install windows 8.1 on my pc which has windows 8 installed. I created a bootable DVD using 'Win7 USB/DVD Download Tool' and it showed a success message at the end.
When I shut down my PC and then restart it to enter BIOS to choose boot order, I choose CD/DVD option but the computer restarts and then directly goes to the screen where I normally choose if I want to start up win7 or win8.
I tried bootable USB but that doesn't even show up in the bios boot order list.
Please help me install this.
Thank you for your time and pardon me if this has been posted in the wrong section. :)