issues booting 8.1 from dvd/usb

[tons-of-fun]

I am trying to upgrade my pc from win7 32 bit to 8.1 64 bit and having some problems. I have gigabyte 78lmt-usb3 mobo running award bios non uefi and I simply cannot get my system to boot from a bootable disk or USB. tested both on my laptop and that seems to boot up just fine. I had this same problem when i was trying to change OS from linux to win7. friend came over and got up a command prompt some how and had to try run some crazy command to make the harddrive delete everything bit by bit. any idea why this is being so challenging?

note i have gone through trying to manually boot from dvd and usb in boot loader and it just boots into windows 7

 

[ASUS ROG]

You probably have to erase Window 7 os first then try to install the new Window 8.1
Use hdd erase to wipe clean your hdd than install new os
http://www.pcworld.com/article/2084...rely-erases-drives-the-old-fashioned-way.html

 

[tons-of-fun]

see... what had happened was i had HDD and rom drives both in sata 2 ports and i guess that was causing an issue with booting from another device. I tried disabling hdd from boot sequence and it still booted into windows 7, i thought it would give me a boot error but what ever. so then i unplugged the hdd and started up my pc and then once i saw the windows 8 start up i plugged my hdd back got an error about device drivers because i forgot to re-enable hdd ended up switching rom drive to sata 3 port and then when i enabled hdd in boot sequence, windos 8 installer popped up and installation went normal.

tldr; problem exists between computer and chair

 

[trents]

I have used that motherboard and had that same problem with not being able to get it to boot from an optical drive or a thumb drive. As I recall, I had to put the optical drive on SATA port 4/5 and configure those for IDE mode. You also have to make sure the boot device is the first one listed in the bios' boot tab under the available hard drives and that it is ahead of the system hard drive in boot order. This board sees a thumb drive as a "USB hard drive" I believe. It is a very finickey motherboard when it comes to booting from some other device besides the system hard drive. The bios is very poorly engineered for this function.