如何彻底删除 Xubuntu 登录页面？

Question

我安装了 Unity，后来又安装了 Xubuntu；现在我删除了 Xubuntu 并切换回 Unity。但是，每次我登录时，首先会出现Unity登录页面，登录后会跳转到xubuntu登录页面。所以我每次都需要录两遍我的密码。我该如何解决这个问题？我试过用unity-tweak-tool --reset-unity命令，但没有用。

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

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
  set have_grubenv=true
  load_env
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="0"
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 recordfail {
  set recordfail=1
  if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; 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
}

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_msdos
insmod ext2
set root='hd0,msdos1'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
else
  search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
fi
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_US
  insmod gettext
fi
terminal_output gfxterm
if [ "${recordfail}" = 1 ] ; then
  set timeout=-1
else
  if [ x$feature_timeout_style = xy ] ; then
    set timeout_style=hidden
    set timeout=0
  # Fallback hidden-timeout code in case the timeout_style feature is
  # unavailable.
  elif sleep --interruptible 0 ; then
    set timeout=0
  fi
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/light-gray
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
function gfxmode {
    set gfxpayload="${1}"
    if [ "${1}" = "keep" ]; then
        set vt_handoff=vt.handoff=7
    else
        set vt_handoff=
    fi
}
if [ "${recordfail}" != 1 ]; then
  if [ -e ${prefix}/gfxblacklist.txt ]; then
    if hwmatch ${prefix}/gfxblacklist.txt 3; then
      if [ ${match} = 0 ]; then
        set linux_gfx_mode=keep
      else
        set linux_gfx_mode=text
      fi
    else
      set linux_gfx_mode=text
    fi
  else
    set linux_gfx_mode=keep
  fi
else
  set linux_gfx_mode=text
fi
export linux_gfx_mode
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
    recordfail
    load_video
    gfxmode $linux_gfx_mode
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    else
      search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    fi
    linux   /boot/vmlinuz-3.13.0-24-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro  quiet splash $vt_handoff
    initrd  /boot/initrd.img-3.13.0-24-generic
}
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
    menuentry 'Ubuntu, with Linux 3.13.0-24-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-24-generic-advanced-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.13.0-24-generic ...'
        linux   /boot/vmlinuz-3.13.0-24-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.13.0-24-generic
    }
    menuentry 'Ubuntu, with Linux 3.13.0-24-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.13.0-24-generic-recovery-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.13.0-24-generic ...'
        linux   /boot/vmlinuz-3.13.0-24-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.13.0-24-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-19-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-19-generic-advanced-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-19-generic ...'
        linux   /boot/vmlinuz-3.11.0-19-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-19-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-19-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-19-generic-recovery-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-19-generic ...'
        linux   /boot/vmlinuz-3.11.0-19-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-19-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-14-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-14-generic-advanced-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-14-generic ...'
        linux   /boot/vmlinuz-3.11.0-14-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-14-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-14-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-14-generic-recovery-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-14-generic ...'
        linux   /boot/vmlinuz-3.11.0-14-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-14-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-12-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-12-generic-advanced-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        gfxmode $linux_gfx_mode
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-12-generic ...'
        linux   /boot/vmlinuz-3.11.0-12-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro  quiet splash $vt_handoff
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-12-generic
    }
    menuentry 'Ubuntu, with Linux 3.11.0-12-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-3.11.0-12-generic-recovery-86a4e1a4-02f7-45b8-91be-738e6c8a08f1' {
        recordfail
        load_video
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        else
          search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
        fi
        echo    'Loading Linux 3.11.0-12-generic ...'
        linux   /boot/vmlinuz-3.11.0-12-generic root=UUID=86a4e1a4-02f7-45b8-91be-738e6c8a08f1 ro recovery nomodeset 
        echo    'Loading initial ramdisk ...'
        initrd  /boot/initrd.img-3.11.0-12-generic
    }
}

### 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_memtest86+ ###
menuentry 'Memory test (memtest86+)' {
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    else
      search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    fi
    knetbsd /boot/memtest86+.elf
}
menuentry 'Memory test (memtest86+, serial console 115200)' {
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint-bios=hd0,msdos1 --hint-efi=hd0,msdos1 --hint-baremetal=ahci0,msdos1  86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    else
      search --no-floppy --fs-uuid --set=root 86a4e1a4-02f7-45b8-91be-738e6c8a08f1
    fi
    linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

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

### BEGIN /etc/grub.d/30_uefi-firmware ###
### END /etc/grub.d/30_uefi-firmware ###

### 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 ###

（PS：我在安装xubuntu之前把登录主题修改成了ubuntu Unity自带的登录主题之一）

Answer 1

看来你的显示管理器设置搞乱了；我不认为这与启动有关（grub 参与了启动画面选择，而不是登录名）。

从虚拟终端尝试此操作（使用 ctrl-alt-F1 并使用您的用户和密码登录；ctrl-alt-F7 返回图形终端）。

sudo dpkg-reconfigure lightdm

（或者如果它不起作用，请用 代替lightdm）gdm。您将看到一个文本窗口；使用 TAB 在选项之间移动，然后使用 ENTER 进行选择 --- 选择lightdmUnity。

然后你可以重新启动它

sudo restart lightdm 

旧的（但相关的）链接这里。

如果仍然不起作用，请尝试重新安装 DM：

sudo apt-get install --reinstall lightdm 

和/或删除 gdm：

sudo apt-get remove --purge gdm

（对此要小心，如果它要求您删除重要的软件包，请不要这样做 --- 否则您的系统可能会无法使用）。

PS：您是否曾修改过 lightdm/gdm 配置目录中的某些文件，以更改登录背景或类似内容？如果是，请在问题中添加该信息，详细说明您做了什么（您修改/添加了哪些文件以及如何修改/添加）。

这是因为如果您修改了某些配置文件，则在重新安装或更新时，系统不会删除或重置您更改的文件。 因此，如果您想返回，您必须手动撤消您手动执行的操作...