Grub not showing after dual boot centos & win 7

[serppower]

Hi, I have installed centos 6.8 alongside windows 7 and the installation detected the "other" OS which is Win7 but after the installation finished and asked me to restart to complete the extra steps like username,,,etc when i restarted it automatically boot to win7 as if Centos is not even exist

Please help.. what can i do to fix that grub loader and make it show? consider i am a newbie at Linux world

The boot in my Bios is set to "Legacy" i thought i would mention that in case it will be helpful to the answer.

Thanks in advance,,

[Macenger]

Try installing GRUB by referring to Procedure 33.5 in the link: https://access.redhat.com/documentation ... Modes.html

[owl102]

The boot in my Bios is set to "Legacy" i thought i would mention that in case it will be helpful to the answer.

Please show the output of "fdisk -l /dev/sda" and "gdisk -l /dev/sda" and "efibootmgr" after booting a Linux live system via USB or CD/DVD in EFI mode. I guess Windows 7 was installed in EFI mode but CentOS 6 was installed in CSM/Legacy mode. This way you have to use the BIOS boot loader to select which OS to boot which you usually enter by pressing F12 during POST screen.

Usually the BIOS prefers EFI systems during boot, and this may be the cause that Windows 7 is booted by default.

BTW: You cannot boot Windows 7 (EFI) from Grub (non-EFI). When Windows 7 is booted it expects a MBR partitioning scheme when booted in non-EFI mode and a GPT partitioning scheme in EFI mode. So Windows 7 can only be started in the correct EFI/CSM/Legacy mode which is the mode which the installation of Windows was made. To resolve this install CentOS in EFI mode as well.