我已经从 DVD 安装了 Ubuntu 16，但仍然只能使用 Windows 10 登录。我选择了“与 Windows 10 一起安装”选项，并让它自动调整磁盘大小。
如何在登录时看到 Ubuntu？
sudo fdisk -l
上面的 cmd 输出：
Disk /dev/ram0: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram1: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram2: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram3: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram4: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram5: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram6: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram7: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram8: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram9: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram10: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram11: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram12: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram13: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram14: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/ram15: 64 MiB, 67108864 bytes, 131072 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/loop0: 1.4 GiB, 1459982336 bytes, 2851528 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 21CEDCE4-4D19-414B-B17E-ABAD653E02D1
Device Start End Sectors Size Type
/dev/sda1 2048 2050047 2048000 1000M Windows recovery environment
/dev/sda2 2050048 2582527 532480 260M EFI System
/dev/sda3 2582528 3606527 1024000 500M Lenovo boot partition
/dev/sda4 3606528 3868671 262144 128M Microsoft reserved
/dev/sda5 3868672 1037878334 1034009663 493.1G Microsoft basic data
/dev/sda6 1902323712 1953523711 51200000 24.4G Windows recovery environment
/dev/sda7 1037879296 1886214143 848334848 404.5G Linux filesystem
/dev/sda8 1886214144 1902323711 16109568 7.7G Linux swap
分区表条目不按磁盘顺序排列。
sudo fdisk -l /dev/sd*
Disk /dev/sda: 931.5 GiB, 1000204886016 bytes, 1953525168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 21CEDCE4-4D19-414B-B17E-ABAD653E02D1
Device Start End Sectors Size Type
/dev/sda1 2048 2050047 2048000 1000M Windows recovery environment
/dev/sda2 2050048 2582527 532480 260M EFI System
/dev/sda3 2582528 3606527 1024000 500M Lenovo boot partition
/dev/sda4 3606528 3868671 262144 128M Microsoft reserved
/dev/sda5 3868672 1037878334 1034009663 493.1G Microsoft basic data
/dev/sda6 1902323712 1953523711 51200000 24.4G Windows recovery environment
/dev/sda7 1037879296 1886214143 848334848 404.5G Linux filesystem
/dev/sda8 1886214144 1902323711 16109568 7.7G Linux swap
Partition table entries are not in disk order.
Disk /dev/sda1: 1000 MiB, 1048576000 bytes, 2048000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x73736572
Device Boot Start End Sectors Size Id Type
/dev/sda1p1 1920221984 3736432267 1816210284 866G 72 unknown
/dev/sda1p2 1936028192 3889681299 1953653108 931.6G 6c unknown
/dev/sda1p3 0 0 0 0B 0 Empty
/dev/sda1p4 27722122 27722568 447 223.5K 0 Empty
Partition 4 does not start on physical sector boundary.
Partition table entries are not in disk order.
Disk /dev/sda2: 260 MiB, 272629760 bytes, 532480 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x500a0dff
Device Boot Start End Sectors Size Id Type
/dev/sda2p1 1948285285 3650263507 1701978223 811.6G 6e unknown
/dev/sda2p2 0 0 0 0B 74 unknown
/dev/sda2p4 28049408 28049848 441 220.5K 0 Empty
Partition 1 does not start on physical sector boundary.
Partition table entries are not in disk order.
Disk /dev/sda3: 500 MiB, 524288000 bytes, 1024000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x500a0dff
Device Boot Start End Sectors Size Id Type
/dev/sda3p1 1948285285 3650263507 1701978223 811.6G 6e unknown
/dev/sda3p2 0 0 0 0B 74 unknown
/dev/sda3p4 28049408 28049848 441 220.5K 0 Empty
Partition 1 does not start on physical sector boundary.
Partition table entries are not in disk order.
Disk /dev/sda4: 128 MiB, 134217728 bytes, 262144 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/sda5: 493.1 GiB, 529412947456 bytes, 1034009663 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x73736572
Device Boot Start End Sectors Size Id Type
/dev/sda5p1 1920221984 3736432267 1816210284 866G 72 unknown
/dev/sda5p2 1936028192 3889681299 1953653108 931.6G 6c unknown
/dev/sda5p3 0 0 0 0B 0 Empty
/dev/sda5p4 27722122 27722568 447 223.5K 0 Empty
Partition 4 does not start on physical sector boundary.
Partition table entries are not in disk order.
Disk /dev/sda6: 24.4 GiB, 26214400000 bytes, 51200000 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos
Disk identifier: 0x73736572
Device Boot Start End Sectors Size Id Type
/dev/sda6p1 1920221984 3736432267 1816210284 866G 72 unknown
/dev/sda6p2 1936028192 3889681299 1953653108 931.6G 6c unknown
/dev/sda6p3 0 0 0 0B 0 Empty
/dev/sda6p4 27722122 27722568 447 223.5K 0 Empty
Partition 4 does not start on physical sector boundary.
Partition table entries are not in disk order.
Disk /dev/sda7: 404.5 GiB, 434347442176 bytes, 848334848 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk /dev/sda8: 7.7 GiB, 8248098816 bytes, 16109568 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
ubuntu@ubuntu:~$
答案1
看起来您可能无意中将 grub 安装在了错误的驱动器上……可能是分区或 USB 驱动器上。
确保 Grub 安装在特定的启动驱动器上（最有可能/dev/sda）。您可以按照以下步骤重新安装 grub：
启动到您的实时媒体（您的实时 ubuntu 安装磁盘或 USB 棒）。运行该Try Ubuntu选项。然后转到终端 shell 并运行以下命令：
步骤1：
$ sudo mount /dev/sdaX /mnt # Make "X" the partition that has Ubuntu installed (i.e. /dev/sda2)
第2步：
$ for i in /sys /proc /run /dev; do sudo mount --bind "$i" "/mnt/$i"; done
步骤3：
$ sudo chroot /mnt
步骤4：
# update-grub
步骤5：
# grub-install /dev/sdX # (x is the hard drive that has linux installed (i.e. /dev/sda)
update-grub
现在重新启动系统。
$ sudo fdisk -l /dev/sd*在我的系统上使用该命令显示：
Device Boot Start End Sectors Size Id Type
/dev/sda1 2048 102402047 102400000 48.8G 83 Linux
/dev/sda2 * 102402048 204802047 102400000 48.8G 83 Linux
/dev/sda3 204802048 245762047 40960000 19.5G 82 Linux swap / Solaris
/dev/sda4 245762048 3907028991 3661266944 1.7T 83 Linux
在此示例中，Linux 安装在/dev/sda1和上/dev/sda2。
最终解决方案
该问题已通过聊天解决，确保安装在 UEFI 模式下执行并选择UbuntuBios 启动选项。
Ubuntu 在 Grub 菜单中同时显示 Windows 和 Ubuntu 菜单选项。如果将 Bio Boot 选项（顺序）设置为，Windows系统将直接启动到 Windows。Windows 无法识别其他安装的操作系统。