Live ISO media rebooting.

[nemomen]

Hello every person over there!
OS and USB pen drive independent. (I hope, it is a question for Hardware category).
Previously I had almost never met with it, but nowadays almost always.
When I use a live ISO media and reboot after, when I hear the bip sign, I try to press the F12 button as quickly I can do it, but the live media boot again, instead of to offer the F8 button for choose the required boot sequence, the hard disk. The main basic boot sequence is CD/DVD > hard drive > removable drive (but it was modified for being able to boot from live media).
The only way to shutdown, remove the USB-stick and then boot normally from the hard drive. As far as I know, the BIOS/UEFI is up-to-date.
I know the general rule, use the USB-media only once for live ISO one, but I do not uphold the law at all times. It works in order as live ISO media, except the rebooting above.
What’s going on?
Thanks for your information in advance.
Nemomen

[zolex]

Hi nemomen,
i don't really get your targets, but it sounds like you can boot from USB when it's connected and you can boot from hardDrive when there is no USB connected....
so... if you are able to boot from both devices, where is the problem exactly?

[nemomen]

Hi Zolex,
sorry, if I was misunderstood. In the cases of I boot from USB (live media) and finish the live session, try to reboot. But I have no chance to change the boot sequence, because the USB boot again before it would be possible. Each time I try, the result the same. When I choose  the shutdown after the finishing of the live session, remove the USB after and start any session, the set boot sequence valid again (CD/DVD>hard drive), so boot from the hard drive.
I do not know, why reboot from the (live) USB again, instead of offering the possibility of the change of the boot sequence normally.
You are right, generally I can boot from any device according to the boot sequence, except when I use live USB session and try to reboot.
Thanks for paying attention of my problem.
nemomen

[zolex]

Sorry for my late response.... ... but this is a "firmware-thing", wich means you have to take a look in your bios/uefi...
In most cases you have to push "f2" or "del" or "f12" immediately after powering on for a few times so you can access the firmware and set your boot order.
In doubt have a look in the manual of your mainboard manufacturer.

[nemomen]

Hi Zolex,
thanks for your respond. I'm gonna check my UEFI/BIOS settings, but, in the past I had never met with this rebooting weirdness of the same equipment.
Perhaps it came from an updating process anytime.
Have a nice weekend!
nemomen