我最近在运行Windows 7的计算机上安装了CentOS7。我进行了双引导安装，并将CentOS安装在了分区中。但是，当我启动机器时，它仅给我两个CentOS选项。它没有给我选择启动Windows 7的选项。如何将Windows 7重新添加到启动选项？
注意：我正在阅读标题为“ 带有Windows的CenTOS 7双启动”的帖子，但是我的/grub文件夹中似乎只有一个splash.xpm.gz文件，没有其他文件。另外，我是Linux的新手，需要逐步进行一些操作。
编辑＃1
我在命令行上得到以下结果：
[root@localhost home]# sudo update-grub
sudo: update-grub: command not found
[root@localhost home]# sudo grub-mkconfig
sudo: grub-mkconfig: command not found
另外，我目前正在研究这些命令可能不适用于CentOS的可能性。例如，在标题为“ RHEL / Fedora / CentOS系统的update-grub是否等效？ ”的U＆L问答以及标题为“ 在Windows之后安装Centos 7并且无法启动到CentOS的 ”的问答中，这似乎暗示我应该重新安装grub2。但是我该怎么做呢？我现在正在学习Linux。
编辑＃2
以下命令确实起作用。这是输出：
[root@localhost home]# sudo grub2-mkconfig 2>/dev/null
#
# 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 'CentOS Linux, with Linux 3.10.0-123.el7.x86_64' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-77a053a9-a71b-43ce-a8d7-1a3418f5b0d9' {
load_video
set gfxpayload=keep
insmod gzio
insmod part_msdos
insmod xfs
set root='hd0,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos5 --hint- efi=hd0,msdos5 --hint-baremetal=ahci0,msdos5 --hint='hd0,msdos5' 589631f1-d5aa-4374-a069-7aae5ca289bc
else
search --no-floppy --fs-uuid --set=root 589631f1-d5aa-4374-a069-7aae5ca289bc
fi
linux16 /vmlinuz-3.10.0-123.el7.x86_64 root=UUID=77a053a9-a71b-43ce-a8d7-1a3418f5b0d9 ro rd.luks.uuid=luks-a45243be-2514-4a81-b7a1-7e4eff712d2d vconsole.font=latarcyrheb-sun16 crashkernel=auto vconsole.keymap=us rd.luks.uuid=luks-5349515e-a082-4ff2-b035-54da7b8d4990 rhgb quiet
initrd16 /initramfs-3.10.0-123.el7.x86_64.img
}
menuentry 'CentOS Linux, with Linux 0-rescue-369d0c1b630b48cc8ef010ceb99bc668' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-369d0c1b630b48cc8ef010ceb99bc668-advanced-77a053a9-a71b-43ce-a8d7-1a3418f5b0d9' {
load_video
insmod gzio
insmod part_msdos
insmod xfs
set root='hd0,msdos5'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos5 --hint-efi=hd0,msdos5 --hint-baremetal=ahci0,msdos5 --hint='hd0,msdos5' 589631f1-d5aa-4374-a069-7aae5ca289bc
else
search --no-floppy --fs-uuid --set=root 589631f1-d5aa-4374-a069-7aae5ca289bc
fi
linux16 /vmlinuz-0-rescue-369d0c1b630b48cc8ef010ceb99bc668 root=UUID=77a053a9-a71b-43ce-a8d7-1a3418f5b0d9 ro rd.luks.uuid=luks-a45243be-2514-4a81-b7a1-7e4eff712d2d vconsole.font=latarcyrheb-sun16 crashkernel=auto vconsole.keymap=us rd.luks.uuid=luks-5349515e-a082-4ff2-b035-54da7b8d4990 rhgb quiet
initrd16 /initramfs-0-rescue-369d0c1b630b48cc8ef010ceb99bc668.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 ###
menuentry 'Windows 7 (loader) (on /dev/sda2)' --class windows --class os $menuentry_id_option 'osprober-chain-386ED4266ED3DB28' {
insmod part_msdos
insmod ntfs
set root='hd0,msdos2'
if [ x$feature_platform_search_hint = xy ]; then
search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos2 --hint-efi=hd0,msdos2 --hint-baremetal=ahci0,msdos2 --hint='hd0,msdos2' 386ED4266ED3DB28
else
search --no-floppy --fs-uuid --set=root 386ED4266ED3DB28
fi
chainloader +1
}
### 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 ###
2
+1询问之前的尝试方式，并记录问题中的尝试。你会好起来的
—
Olivier Dulac 2014年