Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key

azianavc

Reputable
Apr 27, 2014
2
0
4,510
Help please! I enable CSM coz I was trying to boot from a CD. Now my computer says Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key. How do I fix this? :(
 
Solution
What I did was I went to the system Configuration/Boot Mode and replace UEFI Boot to CSM Boot.

Go to same place and change Boot Mode to UEFI + CSM (=Legacy firmware emulation = BIOS).
So you boot by default to hard disk in UEFI mode.

Typing the "boot device selection key" (F10 or F12 or ESC - depends on computer brand) after/during POST
allows you to select boot device - hard disk, CD/DVD, USB, network.

For CD/DVD and USB there are two flavors - UEFI and non-UEFI(=BIOS):
a) select UEFI type of booting from DVD/USB when you install to a GPT style hard disk,
b) select BIOS(CSM/Legacy) type of boot for DVD/USB when installing to MBR style hard disk.

These a) and b) are relevant for Windows 7/8 installation but other OS's like...

Flying-Q

Distinguished
Feb 20, 2006
643
7
19,065
At first sight it suggests your boot media is not bootable. Give us more information so we can narrow down the problem. CSM is an abbreviation for many different things so which one does it mean in this situation? at what stage does the machine say reboot? Is it IMMEDIATELY after Power On Self Test or after the CD first spins up or later than that after some disc activity?
 

azianavc

Reputable
Apr 27, 2014
2
0
4,510


What I did was I went to the system Configuration/Boot Mode and replace UEFI Boot to CSM Boot. My toshiba laptop restarted with a black screen saying 'Reboot and Select proper Boot device or Insert Boot Media in selected Boot device and press a key". Is there a way to revert it back to UEFI Boot?
 

boyans

Distinguished
May 29, 2011
46
0
18,560
What I did was I went to the system Configuration/Boot Mode and replace UEFI Boot to CSM Boot.

Go to same place and change Boot Mode to UEFI + CSM (=Legacy firmware emulation = BIOS).
So you boot by default to hard disk in UEFI mode.

Typing the "boot device selection key" (F10 or F12 or ESC - depends on computer brand) after/during POST
allows you to select boot device - hard disk, CD/DVD, USB, network.

For CD/DVD and USB there are two flavors - UEFI and non-UEFI(=BIOS):
a) select UEFI type of booting from DVD/USB when you install to a GPT style hard disk,
b) select BIOS(CSM/Legacy) type of boot for DVD/USB when installing to MBR style hard disk.

These a) and b) are relevant for Windows 7/8 installation but other OS's like Linux are using the same defaults.
.
 
Solution

Jheng Guo Wu

Reputable
May 26, 2014
1
0
4,510