Can not boot into Windows after installing CentOS

General support questions
User avatar
TrevorH
Forum Moderator
Posts: 20646
Joined: 2009/09/24 10:40:56
Location: Brighton, UK

Re: Can not boot into Windows after installing CentOS

Postby TrevorH » 2017/08/09 22:28:10

Sorry, I'm lost. I suspect what you're looking for is an NTFS partition and you have several there but no idea which one is Windows boot.
CentOS 5 died in March 2017 - migrate NOW!
Full time Geek, part time moderator. Use the FAQ Luke

hunter86_bg
Posts: 738
Joined: 2015/02/17 15:14:33
Location: Bulgaria
Contact:

Re: Can not boot into Windows after installing CentOS

Postby hunter86_bg » 2017/08/09 22:50:10

Just try to mount all partitions as file system type "ntfs" and then try to rebuild the grub menu (while all partitions are mounted) via "grub2-mkconfig -o <your grub.cfg>"

ASCG5000
Posts: 10
Joined: 2017/08/09 12:32:47

Re: Can not boot into Windows after installing CentOS

Postby ASCG5000 » 2017/08/09 23:04:11

TrevorH wrote:Sorry, I'm lost. I suspect what you're looking for is an NTFS partition and you have several there but no idea which one is Windows boot.

Well now I know that is is in /dev/sda2. My issue now is getting it so that I can boot from it.

owl102
Posts: 272
Joined: 2014/06/10 19:13:41

Re: Can not boot into Windows after installing CentOS

Postby owl102 » 2017/08/10 06:20:45

hunter86_bg wrote:Just try to mount all partitions as file system type "ntfs" and then try to rebuild the grub menu (while all partitions are mounted) via "grub2-mkconfig -o <your grub.cfg>"

Since this is an EFI installation this is the wrong way to rebuild the Grub menu. See also: https://access.redhat.com/documentation ... RUB_2.html

However, as long as the output of "os-prober" does not show the Windows installation, any attempt to rebuild the Grub menu is futile anyway (since Grub uses os-prober to detect other OS installations).

BTW: Windows seems to be installed in /dev/sda3. /dev/sda2 is just a "Microsoft Reserved" partition which Windows installation adds since Windows 7 for future use.

But what really makes me wonder is this one: "any time I attempt to boot into Windows via selecting "Windows Boot Manager" in UEFI grubs shows up with only CentOS as an option." Whatever other OS are installed on the hard disks, using the UEFI boot manager should always work. Either the UEFI boot entry for Windows is broken or the Windows installation itself is broken, but the CentOS installation does not touch them at all.

Or CentOS was not installed in UEFI mode but the UEFI of this specific PC prefers booting CSM/Legacy booting from MBR, if a MBR with boot code is found.

What is the output of "efibootmgr"?

ASCG5000
Posts: 10
Joined: 2017/08/09 12:32:47

Re: Can not boot into Windows after installing CentOS

Postby ASCG5000 » 2017/08/10 12:43:50

owl102 wrote:
hunter86_bg wrote:Just try to mount all partitions as file system type "ntfs" and then try to rebuild the grub menu (while all partitions are mounted) via "grub2-mkconfig -o <your grub.cfg>"

Since this is an EFI installation this is the wrong way to rebuild the Grub menu. See also: https://access.redhat.com/documentation ... RUB_2.html

However, as long as the output of "os-prober" does not show the Windows installation, any attempt to rebuild the Grub menu is futile anyway (since Grub uses os-prober to detect other OS installations).

BTW: Windows seems to be installed in /dev/sda3. /dev/sda2 is just a "Microsoft Reserved" partition which Windows installation adds since Windows 7 for future use.

But what really makes me wonder is this one: "any time I attempt to boot into Windows via selecting "Windows Boot Manager" in UEFI grubs shows up with only CentOS as an option." Whatever other OS are installed on the hard disks, using the UEFI boot manager should always work. Either the UEFI boot entry for Windows is broken or the Windows installation itself is broken, but the CentOS installation does not touch them at all.

Or CentOS was not installed in UEFI mode but the UEFI of this specific PC prefers booting CSM/Legacy booting from MBR, if a MBR with boot code is found.

What is the output of "efibootmgr"?


That is what is confusing me: I downloaded and burned CentOS via the Windows installation on this computer and it worked up until I installed CentOS. So it has to be something wrong with how I installed CentOS.

Here is the output to efibootmgr:

Code: Select all

[root@localhost ~]# efibootmgr
BootCurrent: 0001
Timeout: 0 seconds
BootOrder: 0001,0000,0004,0005,0006,0002,0003,0007
Boot0000* Windows Boot Manager
Boot0001* CentOS Linux
Boot0002* NetWork
Boot0003* Hard Drive
Boot0004* TEST
Boot0005* Onboard NIC (IPV4)
Boot0006* Onboard NIC (IPV6)
Boot0007  Second HDD
[root@localhost ~]#


The 'TEST' option was my attempt at trying to manually add windows (does not work).

When I select Windows Boot Manager, I still boot into CentOS.

owl102
Posts: 272
Joined: 2014/06/10 19:13:41

Re: Can not boot into Windows after installing CentOS

Postby owl102 » 2017/08/10 15:59:41

ASCG5000 wrote:Boot0001* CentOS Linux

So CentOS was installed correctly in UEFI mode, which is good news.

Now to the non-working Microsoft boot entry: Could you please post the output of:

Code: Select all

efibootmgr -v
blkid
ls -lR /boot/efi

(everything as root)

The 'TEST' option was my attempt at trying to manually add windows (does not work).

How have you tried it?

ASCG5000
Posts: 10
Joined: 2017/08/09 12:32:47

Re: Can not boot into Windows after installing CentOS

Postby ASCG5000 » 2017/08/11 02:47:15

Code: Select all

[root@localhost ~]# efibootmgr -v
BootCurrent: 0001
Timeout: 0 seconds
BootOrder: 0001,0000,0004,0005,0006,0002,0003,0007
Boot0000* Windows Boot Manager   Vendor(99e275e7-75a0-4b37-a2e6-c5385e6c00cb,)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...................
Boot0001* CentOS Linux   HD(1,800,fa000,bb3cd039-3735-4054-bfea-b3bdca23de07)File(\EFI\centos\shim.efi)
Boot0002* NetWork   BIOS(4,0,00)..GO..NO........k.N.e.t.W.o.r.k........................rN.D+..,.\..........<..Gd-.;.A..MQ..L.R.e.a.l.t.e.k. .P.X.E. .B.0.4. .D.0.0.......BO
Boot0003* Hard Drive   BIOS(1,0,00)..GO..NO........o.H.a.r.d. .D.r.i.v.e...................A..........................>..Gd-.;.A..MQ..L.5.1.5.4.5.9.0.4.7.6.7.1. . . . . . . . .......BO
Boot0004* TEST   HD(1,800,fa000,bb3cd039-3735-4054-bfea-b3bdca23de07)File(\EFI\BOOT\BOOTX64.EFI)
Boot0005* Onboard NIC (IPV4)   ACPI(a0341d0,0)PCI(1c,4)PCI(0,0)MAC(MAC(00e04c680037,0)..BO
Boot0006* Onboard NIC (IPV6)   ACPI(a0341d0,0)PCI(1c,4)PCI(0,0)MAC(MAC(00e04c680037,0)030d3c000000000000000000000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000..BO
Boot0007  Second HDD   BIOS(6,0,00)..GO..NO........o.S.e.c.o.n.d. .H.D.D...................A..........................>..Gd-.;.A..MQ..L. . . . . . .3.S.4.1.B.J.G.0.0.A.4.2.2.0.......BO
[root@localhost ~]# blkid
/dev/sdb3: LABEL="cl" UUID="0f4f4ecf-99a7-4091-a0fd-516c477e10b6" UUID_SUB="ae2dd37f-cbb3-4fac-af78-0b955e85722c" TYPE="btrfs" PARTUUID="087b2542-119c-43dd-91d5-d74b5bbff84d"
/dev/sda1: SEC_TYPE="msdos" UUID="4723-6D0E" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="bb3cd039-3735-4054-bfea-b3bdca23de07"
/dev/sdb2: LABEL="DATA" UUID="2EEE2622EE25E337" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="2defc8d4-832e-4cc8-a849-d138567d2679"
/dev/sda3: LABEL="OS" UUID="9E62196F62194E01" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="8ccdf825-754f-4f4f-8a7a-837ee42ed87a"
/dev/sda4: LABEL="WINRETOOLS" UUID="1AB4D30DB4D2E9F1" TYPE="ntfs" PARTUUID="9cc806aa-dd70-4ef2-89a0-5fe36706b676"
/dev/sda5: LABEL="Image" UUID="BE8AD3D38AD385F5" TYPE="ntfs" PARTUUID="e30d4ab7-89d1-4b15-8d43-e3c05bc88bb8"
/dev/sdb1: PARTLABEL="Microsoft reserved partition" PARTUUID="53184100-b296-48dc-bf40-db0d7fb30238"
/dev/sda2: PARTLABEL="Microsoft reserved partition" PARTUUID="ea4277b9-7240-42ec-aca1-2687cd7048cf"
[root@localhost ~]# ls -lr /boot/efi
total 8
drwx------. 4 root root 8192 Aug  8 10:00 EFI


This is the point where I have little idea what I am doing, so apologies for anything dumb I say.

owl102 wrote:
The 'TEST' option was my attempt at trying to manually add windows (does not work).

How have you tried it?


I set it up in the BIOS under "Add UEFI Boot option" Probably did not do anything.

owl102
Posts: 272
Joined: 2014/06/10 19:13:41

Re: Can not boot into Windows after installing CentOS

Postby owl102 » 2017/08/11 15:22:20

ASCG5000 wrote:Boot0000* Windows Boot Manager Vendor(99e275e7-75a0-4b37-a2e6-c5385e6c00cb,)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...................

Yes, this boot entry is definitely broken. It points to a partition with the UUID 99e275e7-75a0-4b37-a2e6-c5385e6c00cb but such a partition couldn't be found on your system. I guess you have formatted this partition accidentally.

Boot0004* TEST HD(1,800,fa000,bb3cd039-3735-4054-bfea-b3bdca23de07)File(\EFI\BOOT\BOOTX64.EFI)

This boot entry will not boot MS Windows since it points to the file EFI/BOOT/BOOTX64.EFI which is part of CentOS and not a part of MS-Windows.

[root@localhost ~]# ls -lr /boot/efi

I meant "ls -lR /boot/efi" (with a large "R" in it). Please repeat.

I set it up in the BIOS under "Add UEFI Boot option" Probably did not do anything.

Try setting up another boot entry this way, but this time let it point to the file \EFI\Microsoft\Boot\bootmgfw.efi on your EFI System Partition.

ASCG5000
Posts: 10
Joined: 2017/08/09 12:32:47

Re: Can not boot into Windows after installing CentOS

Postby ASCG5000 » 2017/08/12 19:18:41

owl102 wrote:I meant "ls -lR /boot/efi" (with a large "R" in it). Please repeat.

Code: Select all

[root@localhost ~]# ls -lR /boot/efi
/boot/efi:
total 8
drwx------. 4 root root 8192 Aug  8 10:00 EFI

/boot/efi/EFI:
total 16
drwx------. 2 root root 8192 Aug  8 10:00 BOOT
drwx------. 3 root root 8192 Aug  8 11:08 centos

/boot/efi/EFI/BOOT:
total 1344
-rwx------. 1 root root 1296176 Dec  7  2015 BOOTX64.EFI
-rwx------. 1 root root   73240 Dec  7  2015 fallback.efi

/boot/efi/EFI/centos:
total 5848
-rwx------. 1 root root     128 Dec  7  2015 BOOT.CSV
drwx------. 2 root root    8192 Aug  8 09:58 fonts
-rwx------. 1 root root 1025920 Nov 22  2016 gcdx64.efi
-rwx------. 1 root root    4230 Aug  8 11:08 grub.cfg
-rwx------. 1 root root    4230 Aug  8 10:13 grub.cfg.1502204277.rpmsave
-rwx------. 1 root root    1024 Aug  8 11:08 grubenv
-rwx------. 1 root root 1025920 Nov 22  2016 grubx64.efi
-rwx------. 1 root root 1283952 Dec  7  2015 MokManager.efi
-rwx------. 1 root root 1291512 Dec  7  2015 shim-centos.efi
-rwx------. 1 root root 1296176 Dec  7  2015 shim.efi

/boot/efi/EFI/centos/fonts:
total 2504
-rwx------. 1 root root 2560080 Nov 22  2016 unicode.pf2
[root@localhost ~]#

owl102 wrote:Try setting up another boot entry this way, but this time let it point to the file \EFI\Microsoft\Boot\bootmgfw.efi on your EFI System Partition.

How exactly can I do this?

owl102
Posts: 272
Joined: 2014/06/10 19:13:41

Re: Can not boot into Windows after installing CentOS

Postby owl102 » 2017/08/13 07:41:39

ASCG5000 wrote:# ls -lR /boot/efi

Unfortunately this output shows no sign of a Microsoft Windows EFI boot loader.

So much for the bad news, here comes the good ones:

- Finally we know what went wrong: During installation of CentOS the EFI System Partition was marked to get formatted. (This explains were the partition with the UUID 99e275e7-75a0-4b37-a2e6-c5385e6c00cb has gone, too. This was the EFI System Partition and during formatting it got a new UUID.)

- Since CentOS installation does not touch other partitions (as long as one does not explicitly told to do so) I strongly assume your Windows installation of /dev/sda3 is still intact, including your account and all your data.

What to do now: The Microsoft EFI boot loader needs to be restored. This can only be done by Microsoft Windows, so you have to boot a Windows installation DVD/USB (in UEFI mode) and pick the "Repair Boot" option. I have never done this myself, so I cannot help here, but searching the Web for "Repair Microsoft Windows 10 EFI boot" should give valuable results. For example this one looks promising: http://www.dell.com/support/article/de/ ... pc?lang=en
Last edited by owl102 on 2017/08/15 07:21:16, edited 1 time in total.