How to Dual boot system windows 10 and Linux(windows with centos 7 or Fedora)?

Dual boot system windows 10 and Linux

Editing grub file in centos 7

While Dual booting your system with windows and centos 7, one common problem arises ie. menuentry of windows disappears .

To retrieve the windows option do needful

Edit

– vim /etc/grub2.cfg

This is real grub2.cfg you have to edit this file

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub2-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
set pager=1

if [ -s $prefix/grubenv ]; then
load_env
fi
if [ "${next_entry}" ] ; then
set default="${next_entry}"
set next_entry=
save_env next_entry
set boot_once=true
else
set default="${saved_entry}"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
else
menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}

function load_video {
if [ x$feature_all_video_module = xy ]; then
insmod all_video
else
insmod efi_gop
insmod efi_uga
insmod ieee1275_fb
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
fi
}

terminal_output console
if [ x$feature_timeout_style = xy ] ; then
set timeout_style=menu
set timeout=5
# Fallback normal timeout code in case the timeout_style feature is
# unavailable.
else
set timeout=5
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Red Hat Enterprise Linux Server, with Chirag' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-71253481-a0a3-49ce-8148-d5723a45eacc' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 --hint='hd0,msdos6' 71253481-a0a3-49ce-8148-d5723a45eacc
else
search --no-floppy --fs-uuid --set=root 71253481-a0a3-49ce-8148-d5723a45eacc
fi
linux16 /boot/vmlinuz-3.10.0-123.el7.x86_64 root=UUID=71253481-a0a3-49ce-8148-d5723a45eacc ro vconsole.keymap=us vconsole.font=latarcyrheb-sun16 rhgb quiet LANG=en_IN.UTF-8
initrd16 /boot/initramfs-3.10.0-123.el7.x86_64.img
}
menuentry 'Red Hat Enterprise Linux Server, with Linux 0-rescue-15edb448df524bef8f029db39d88d859' --class red --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-15edb448df524bef8f029db39d88d859-advanced-71253481-a0a3-49ce-8148-d5723a45eacc' {
load_video
insmod gzio
insmod part_msdos
insmod ext2
set root='hd0,msdos6'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos6 --hint-efi=hd0,msdos6 --hint-baremetal=ahci0,msdos6 --hint='hd0,msdos6' 71253481-a0a3-49ce-8148-d5723a45eacc
else
search --no-floppy --fs-uuid --set=root 71253481-a0a3-49ce-8148-d5723a45eacc
fi
linux16 /boot/vmlinuz-0-rescue-15edb448df524bef8f029db39d88d859 root=UUID=71253481-a0a3-49ce-8148-d5723a45eacc ro vconsole.keymap=us vconsole.font=latarcyrheb-sun16 rhgb quiet
initrd16 /boot/initramfs-0-rescue-15edb448df524bef8f029db39d88d859.img
}

 

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_ppc_terminfo ###
### END /etc/grub.d/20_ppc_terminfo ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f ${config_directory}/custom.cfg ]; then
source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###

————————————————————————————

We have to add the new menuentry for windows –

Take backup of original grub2.cfg file

Copy the below given script and paste it in original grub2.cfg file

menuentry 'windows 7' {
insmod part_msdos
insmod_ntfs
et root='hd0,msdos1'
chainloader +1
}

Watch steps –