My dual-boot FC25/W10 Dell Inspiron 2-in-1 has been working fine for a month.

Now I can only boot into Win 10, and to do that I need to enter the system set-up.

Upon power up, the machine ends up with a grub> prompt. So I've lost the grub boot menu.

I've tried to boot by hand using the information in the following post as a guide:

http://forums.fedoraforum.org/showthread.php?t=306810

The system tries to boot, but fails with "ACPI Error"s, and seems to just hang.

I wrote a Boot Repair Disk, but that eventually fails and quits. (I've used that successfully in the past.)

Any ideas on how to get my grub menu back?

Sounds like all you need to do is re-install Grub.
But before you do boot up your Live Fedora CD or USB and see if the Fedora partitions are still there with this command as root.
https://www.reddit.com/r/Fedora/comm...einstall_grub/

Is your Dell a UEFI machine?

If so, the instructions are different for that type of machine.
http://linuxbsdos.com/2016/12/01/dua...uefi-firmware/

If you have the boot repair software you can select the Create BootInfo Summary option and post a link to the output as it will show details on your system.

I checked using a live CD and all eight partitions are reported.

Yes, the machine is a UEFI machine. I've got Secure Boot turned off.
That happened while I was struggling in vain to restore the grub menu.

I don't get the instructions at the link you posted for UEFI. Those
instructions are for how to create a dual-boot machine. I already
created it over a month ago, and it has been working fine until today.

Should I follow the "Reinstall grub" instructions at the first link?

Thanks much

That's good that your FC are there.

Post the output of the bootinfoscript for yancek so he can take a look at it.

Paste the RESULTS.txt file on paste bin or tiny paste if you could.

Is their an option in the bios setup for os selection of either 8.x or windows 7? If so change to windows 7, then try to boot manually

Boot Info Script 0.61 [1 April 2012]


============================= Boot Info Summary: ===============================

=> No boot loader is installed in the MBR of /dev/sda.

sda1: __________________________________________________________________________

File system: vfat
Boot sector type: Unknown
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files: /efi/Boot/bootx64.efi /efi/Boot/fallback.efi
/efi/fedora/fwupx64.efi /efi/fedora/gcdx64.efi
/efi/fedora/grubx64.efi /efi/fedora/MokManager.efi
/efi/fedora/shim.efi /efi/fedora/shim-fedora.efi

sda2: __________________________________________________________________________

File system:
Boot sector type: -
Boot sector info:
Mounting failed: mount: unknown filesystem type ''

sda3: __________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files: /bootmgr /Windows/System32/winload.exe

sda4: __________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:

sda5: __________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:

sda6: __________________________________________________________________________

File system: ntfs
Boot sector type: Windows Vista/7: NTFS
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:

sda7: __________________________________________________________________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System:
Boot files:

sda8: __________________________________________________________________________

File system: LVM2_member
Boot sector type: -
Boot sector info:

fedora_spock-root': ____________________________________________________________

File system:
Boot sector type: Unknown
Boot sector info:
Mounting failed: mount: unknown filesystem type ''
mount: unknown filesystem type ''

fedora_spock-home': ____________________________________________________________

File system:
Boot sector type: Unknown
Boot sector info:
Mounting failed: mount: unknown filesystem type ''
mount: unknown filesystem type ''
mount: unknown filesystem type ''

fedora_spock-swap': ____________________________________________________________

File system:
Boot sector type: Unknown
Boot sector info:
Mounting failed: mount: unknown filesystem type ''
mount: unknown filesystem type ''
mount: unknown filesystem type ''
mount: unknown filesystem type ''

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________
Disk /dev/sda: 465.8 GiB, 500107862016 bytes, 976773168 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

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sda1 1 976,773,167 976,773,167 ee GPT


GUID Partition Table detected.

Partition Start Sector End Sector # of Sectors System
/dev/sda1 2,048 1,026,047 1,024,000 EFI System partition
/dev/sda2 1,026,048 1,288,191 262,144 Microsoft Reserved Partition (W
indows)
/dev/sda3 1,288,192 502,829,055 501,540,864 Data partition (Windows/Linux)
/dev/sda4 953,389,056 954,310,655 921,600 Windows Recovery Environment (W
indows)
/dev/sda5 954,310,656 974,516,223 20,205,568 Windows Recovery Environment (W
indows)
/dev/sda6 974,518,272 976,773,119 2,254,848 Windows Recovery Environment (W
indows)
/dev/sda7 502,829,056 503,853,055 1,024,000 Data partition (Linux)
/dev/sda8 503,853,056 953,389,055 449,536,000 Logical Volume Manager (LVM) pa
rtition (Linux)

"blkid" output: ________________________________________________________________

Device UUID TYPE LABEL


/dev/disk/by-label/Fedora-WS-Live-25_A-2 2016-08-25-02-42-14-00 iso96
60 Fedora-WS-Live-25_A-2
/dev/loop0 squashfs
/dev/loop1 7cf546ab-4e09-4386-abbf-8c9648903f06 ext4 Anaconda
/dev/mapper/fedora_spock-home 539b7bac-7643-4b14-8246-7903aac81107 ext4
/dev/mapper/fedora_spock-root ddd5c95b-ceab-4036-b7e5-a405b4ecb916 ext4
/dev/mapper/fedora_spock-swap 442f2d11-6ea0-4f64-8b32-d60ff1939dc2 swap
/dev/mapper/live-base 7cf546ab-4e09-4386-abbf-8c9648903f06 ext4 Anaconda
/dev/mapper/live-rw 7cf546ab-4e09-4386-abbf-8c9648903f06 ext4 Anaconda
/dev/sda1 F0EB-AE47 vfat ESP
/dev/sda2
/dev/sda3 C2D43ECCD43EC309 ntfs OS
/dev/sda4 2EFA08DCFA08A267 ntfs WINRETOOLS
/dev/sda5 5AA4097FA4095F3F ntfs Image
/dev/sda6 EC8C7A478C7A0C78 ntfs DELLSUPPORT
/dev/sda7 943d5925-dfca-4578-8857-6bddaa23fb21 ext4
/dev/sda8 jWDrEw-tTjx-dO8F-XdHG-9zEw-wYcH-hN3nie LVM2_member

========================= "ls -R /dev/mapper/" output: =========================

/dev/mapper:
control
fedora_spock-home
fedora_spock-root
fedora_spock-swap
live-base
live-rw

================================ Mount points: =================================

Device Mount_Point Type Options

/dev/mapper/live-rw / ext4 (rw,relatime,seclabel,data=or
dered)
/dev/sr0 /run/initramfs/live iso9660 (ro,relatime)


=================== sda7: Location of files loaded by Grub: ====================

GiB - GB File Fragment(s)


================= sda7: Location of files loaded by Syslinux: ==================

GiB - GB File Fragment(s)


============== sda7: Version of COM32(R) files used by Syslinux: ===============

extlinux/cat.c32 : not a COM32/COM32R module
extlinux/chain.c32 : not a COM32/COM32R module
extlinux/cmd.c32 : not a COM32/COM32R module
extlinux/cmenu.c32 : not a COM32/COM32R module
extlinux/config.c32 : not a COM32/COM32R module
extlinux/cptime.c32 : not a COM32/COM32R module
extlinux/cpu.c32 : not a COM32/COM32R module
extlinux/cpuid.c32 : not a COM32/COM32R module
extlinux/cpuidtest.c32 : not a COM32/COM32R module
extlinux/debug.c32 : not a COM32/COM32R module
extlinux/dhcp.c32 : not a COM32/COM32R module
extlinux/dir.c32 : not a COM32/COM32R module
extlinux/disk.c32 : not a COM32/COM32R module
extlinux/dmi.c32 : not a COM32/COM32R module
extlinux/dmitest.c32 : not a COM32/COM32R module
extlinux/elf.c32 : not a COM32/COM32R module
extlinux/ethersel.c32 : not a COM32/COM32R module
extlinux/gfxboot.c32 : not a COM32/COM32R module
extlinux/gpxecmd.c32 : not a COM32/COM32R module
extlinux/hdt.c32 : not a COM32/COM32R module
extlinux/hexdump.c32 : not a COM32/COM32R module
extlinux/host.c32 : not a COM32/COM32R module
extlinux/ifcpu64.c32 : not a COM32/COM32R module
extlinux/ifcpu.c32 : not a COM32/COM32R module
extlinux/ifmemdsk.c32 : not a COM32/COM32R module
extlinux/ifplop.c32 : not a COM32/COM32R module
extlinux/kbdmap.c32 : not a COM32/COM32R module
extlinux/kontron_wdt.c32 : not a COM32/COM32R module
extlinux/ldlinux.c32 : not a COM32/COM32R module
extlinux/lfs.c32 : not a COM32/COM32R module
extlinux/libcom32.c32 : not a COM32/COM32R module
extlinux/libgpl.c32 : not a COM32/COM32R module
extlinux/liblua.c32 : not a COM32/COM32R module
extlinux/libmenu.c32 : not a COM32/COM32R module
extlinux/libutil.c32 : not a COM32/COM32R module
extlinux/linux.c32 : not a COM32/COM32R module
extlinux/ls.c32 : not a COM32/COM32R module
extlinux/lua.c32 : not a COM32/COM32R module
extlinux/mboot.c32 : not a COM32/COM32R module
extlinux/meminfo.c32 : not a COM32/COM32R module
extlinux/menu.c32 : not a COM32/COM32R module
extlinux/pci.c32 : not a COM32/COM32R module
extlinux/pcitest.c32 : not a COM32/COM32R module
extlinux/pmload.c32 : not a COM32/COM32R module
extlinux/poweroff.c32 : not a COM32/COM32R module
extlinux/prdhcp.c32 : not a COM32/COM32R module
extlinux/pwd.c32 : not a COM32/COM32R module
extlinux/pxechn.c32 : not a COM32/COM32R module
extlinux/reboot.c32 : not a COM32/COM32R module
extlinux/rosh.c32 : not a COM32/COM32R module
extlinux/sanboot.c32 : not a COM32/COM32R module
extlinux/sdi.c32 : not a COM32/COM32R module
extlinux/sysdump.c32 : not a COM32/COM32R module
extlinux/syslinux.c32 : not a COM32/COM32R module
extlinux/vesa.c32 : not a COM32/COM32R module
extlinux/vesainfo.c32 : not a COM32/COM32R module
extlinux/vesamenu.c32 : not a COM32/COM32R module
extlinux/vpdtest.c32 : not a COM32/COM32R module
extlinux/whichsys.c32 : not a COM32/COM32R module
extlinux/zzjson.c32 : not a COM32/COM32R module

======================== Unknown MBRs/Boot Sectors/etc: ========================

Unknown BootLoader on sda1

00000000 eb 58 90 4d 53 44 4f 53 35 2e 30 00 02 08 3e 18 |.X.MSDOS5.0...>.|
00000010 02 00 00 00 00 f8 00 00 3f 00 ff 00 00 08 00 00 |........?.......|
00000020 00 a0 0f 00 e1 03 00 00 00 00 00 00 02 00 00 00 |................|
00000030 01 00 06 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000040 80 00 29 47 ae eb f0 4e 4f 20 4e 41 4d 45 20 20 |..)G...NO NAME |
00000050 20 20 46 41 54 33 32 20 20 20 33 c9 8e d1 bc f4 | FAT32 3.....|
00000060 7b 8e c1 8e d9 bd 00 7c 88 56 40 88 4e 02 8a 56 |{......|.V@.N..V|
00000070 40 b4 41 bb aa 55 cd 13 72 10 81 fb 55 aa 75 0a |@.A..U..r...U.u.|
00000080 f6 c1 01 74 05 fe 46 02 eb 2d 8a 56 40 b4 08 cd |...t..F..-.V@...|
00000090 13 73 05 b9 ff ff 8a f1 66 0f b6 c6 40 66 0f b6 |.s......f...@f..|
000000a0 d1 80 e2 3f f7 e2 86 cd c0 ed 06 41 66 0f b7 c9 |...?.......Af...|
000000b0 66 f7 e1 66 89 46 f8 83 7e 16 00 75 39 83 7e 2a |f..f.F..~..u9.~*|
000000c0 00 77 33 66 8b 46 1c 66 83 c0 0c bb 00 80 b9 01 |.w3f.F.f........|
000000d0 00 e8 2c 00 e9 a8 03 a1 f8 7d 80 c4 7c 8b f0 ac |..,......}..|...|
000000e0 84 c0 74 17 3c ff 74 09 b4 0e bb 07 00 cd 10 eb |..t.<.t.........|
000000f0 ee a1 fa 7d eb e4 a1 7d 80 eb df 98 cd 16 cd 19 |...}...}........|
00000100 66 60 80 7e 02 00 0f 84 20 00 66 6a 00 66 50 06 |f`.~.... .fj.fP.|
00000110 53 66 68 10 00 01 00 b4 42 8a 56 40 8b f4 cd 13 |Sfh.....B.V@....|
00000120 66 58 66 58 66 58 66 58 eb 33 66 3b 46 f8 72 03 |fXfXfXfX.3f;F.r.|
00000130 f9 eb 2a 66 33 d2 66 0f b7 4e 18 66 f7 f1 fe c2 |..*f3.f..N.f....|
00000140 8a ca 66 8b d0 66 c1 ea 10 f7 76 1a 86 d6 8a 56 |..f..f....v....V|
00000150 40 8a e8 c0 e4 06 0a cc b8 01 02 cd 13 66 61 0f |@............fa.|
00000160 82 74 ff 81 c3 00 02 66 40 49 75 94 c3 42 4f 4f |.t.....f@Iu..BOO|
00000170 54 4d 47 52 20 20 20 20 00 00 00 00 00 00 00 00 |TMGR ........|
00000180 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
000001a0 00 00 00 00 00 00 00 00 00 00 00 00 0d 0a 44 69 |..............Di|
000001b0 73 6b 20 65 72 72 6f 72 ff 0d 0a 50 72 65 73 73 |sk error...Press|
000001c0 20 61 6e 79 20 6b 65 79 20 74 6f 20 72 65 73 74 | any key to rest|
000001d0 61 72 74 0d 0a 00 00 00 00 00 00 00 00 00 00 00 |art.............|
000001e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000001f0 00 00 00 00 00 00 00 00 ac 01 b9 01 00 00 55 aa |..............U.|
00000200

Unknown BootLoader on fedora_spock-root'


Unknown BootLoader on fedora_spock-home'


Unknown BootLoader on fedora_spock-swap'


=============================== StdErr Messages: ===============================

cat: /tmp/BootInfo-413TX2Wr/Tmp_Log: No such file or directory
cat: /tmp/BootInfo-413TX2Wr/Tmp_Log: No such file or directory
Failed to find logical volume "fedora_spock/root'"
Failed to find logical volume "fedora_spock/root'"
Failed to find logical volume "fedora_spock/root'"
hexdump: /dev/mapper/fedora_spock-root': No such file or directory
hexdump: stdin: Bad file descriptor
hexdump: /dev/mapper/fedora_spock-root': No such file or directory
hexdump: all input file arguments failed
Failed to find logical volume "fedora_spock/home'"
Failed to find logical volume "fedora_spock/home'"
Failed to find logical volume "fedora_spock/home'"
hexdump: /dev/mapper/fedora_spock-home': No such file or directory
hexdump: stdin: Bad file descriptor
hexdump: /dev/mapper/fedora_spock-home': No such file or directory
hexdump: all input file arguments failed
Failed to find logical volume "fedora_spock/swap'"
Failed to find logical volume "fedora_spock/swap'"
Failed to find logical volume "fedora_spock/swap'"
hexdump: /dev/mapper/fedora_spock-swap': No such file or directory
hexdump: stdin: Bad file descriptor
hexdump: /dev/mapper/fedora_spock-swap': No such file or directory
hexdump: all input file arguments failed
mdadm: No arrays found in config file or automatically

You have an EFI/GPT system and you have the fedora efi files on the EFI partition. Scrolling down your output a little further, there is no indication of boot files for fedora on any partition. They usually show in the script but not always. You don't have any grub.cfg file showing in the output which is almost always shown. You have 'unknown bootloader' on each of your LVM partitions and on sda7 you have a number of syslinux files which I would not expect to see. I don't use Fedora or LVM so I don't know what the problem would be. Were there any changes made to hardware/software immediately prior to this happening or were there any major updates on windows?

The last time the system was up it was in FC 25 and I believe I had done

dnf update

The last time the system was booted into W10 I believe there was an update.

My memory has faded, and I wasn't expecting trouble, as these kinds of updates
are routine on my various dual-boot machines.

What do you think my options are? Reinstall grub? Reinstall FC25?

maybe by adding when you was trying to boot manually will help. also where ? is the partition number will allow you to see what kernel to use.

'Some' windows 10 updates will mess up booting on EFI systems so that might be it. I don't use Fedora so I don't know what 'dnf update' does. Doubt it would ruin your Grub bootloader. I doubt re-installing Grub will resolve the problem as you don't have a grub.cfg file and that isn't created when reinstalling Grub. If you could chroot to Fedora and run grub-mkconfig it might help. I'm not sure how those Syslinux files got on your partition?

maybe this will help: http://www.terminalinflection.com/manual-grub-boot/

When I ran Fedora 'dnf update' pulled in security updates, upgrades to the kernel if there were any upgrades to the kernel,apply patches,update all of the installed pkg's on the system and the like from the FC repos.

I've never had dnf wreck Grub for the duration that I ran Fedora.

-::-A fresh install may prove well in this case since like yancek said: there isn't a grub.cfg file.-::-

Grub depends on that file.

Chroot links-
https://docs.fedoraproject.org/en-US...mode-boot.html
http://unix.stackexchange.com/questi...l-mnt-is-empty

Thanks all for your help and suggestions.

I have to bring this computer on an overseas trip very soon and I just couldn't keep trying to recover both W10 and FC25. So I started over, abandoned W10, and reinstalled FC25. Maybe I'll reconfigure after the trip, attempting the dual-boot again. But probably not since I believe W10 is the culprit in wrecking the original dual-boot config.