Problems with CentOS 7 and Windows 7 Dualboot

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NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/02/25 21:24:04

I am new to Linux.

I installed CentOS 7 after Windows 7, but I cant boot in CentOS. My system continues directly to Windows 7. There is no option to boot in CentOs

I disables UEFI in my BIOS, I couldnt instal CentOS without doing so. When I tried installing CentOS with UEFI enabled i got the error "EFI system partition on a GPT-formatted disk mounted at /boot/efi".

So I installed CentOS without UEFI, no problems during installation, however now I cant boot into CentOS.

What am I diong wrong?

owl102
Posts: 413
Joined: 2014/06/10 19:13:41

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by owl102 » 2018/02/25 22:49:42

If Windows 7 is installed in UEFI mode, you should install CentOS in UEFI mode as well.

If Windows 7 is installed in BIOS/CSM/Legacy mode, you should install CentOS in BIOS/CSM/Legacy mode as well.

Otherwise the Linux bootloader GRUB will not be able to start Windows 7 from its bootmenu.
NP77 wrote:When I tried installing CentOS with UEFI enabled i got the error "EFI system partition on a GPT-formatted disk mounted at /boot/efi".
When installing CentOS (or any other GNU/Linux) one need to mount the EFI System Partition (ESP) as /boot/efi, and to make sure it's not marked as to-be-formatted during installation.
German speaking forum for Fedora and CentOS: https://www.fedoraforum.de/

NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/02/26 23:38:12

I disabled EUFI in my BIOS. I flashed my BIOS, not realizing that it would re-enable UEFI

The CentOs installation I had already installed now booted, but no bootloader. No option to select Windows.

When I booted into Linux I was prompted to accept the licence agreement, but my mouse and keyboard were disabled. I couldnt accept. :shock:

Windows was not available, so I re-installed Windows 7. Still not realizing UEFI was enabled again. Then I re-installed CentOs again, same problem, mouse and keyboard are not responding and no bootloader.
When installing CentOS (or any other GNU/Linux) one need to mount the EFI System Partition (ESP) as /boot/efi, and to make sure it's not marked as to-be-formatted during installation.
How do I do this, I also have a CentOs live CD. Does that help?

owl102
Posts: 413
Joined: 2014/06/10 19:13:41

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by owl102 » 2018/02/27 08:50:49

NP77 wrote:The CentOs installation I had already installed now booted, but no bootloader. No option to select Windows.
This is the default behaviour, at least when installing without UEFI. After installation of CentOS, do:

Code: Select all

yum install epel-release
yum install ntfs-3g
Afterwards

Code: Select all

os-prober
should find your Windows installation. If this is the case, re-generate the Grub menu:

Code: Select all

grub2-mkconfig -o /boot/grub2/grub.cfg
(See also: https://wiki.centos.org/HowTos/Grub2)

When installed in UEFI mode none of the steps above are necessary (or even wrong).
German speaking forum for Fedora and CentOS: https://www.fedoraforum.de/

NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/02/27 18:05:55

NP77 wrote:When I booted into Linux I was prompted to accept the licence agreement, but my mouse and keyboard were disabled. I couldnt accept. :shock:
I cant type anything or start up a terminal, my keyboard and mouse dont work after a reboot. In the installer my keyboard and mouse work just fine.

I dont know how to solve this.

NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/03/01 22:43:06

I bought my system in 2012, it's a Medion PC.

Does booting in UEFI have anything to do with CenOs7 not recognizing My Keyboard and mouse? Is there any point in reinstalling windows 7 with UEFI disabled?

I'm really stumped on this one. :?

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TrevorH
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Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by TrevorH » 2018/03/01 23:21:24

How did you do the CentOS install? Did you use a USB stick and some dodgy utility to copy the iso image file to it? Some of the utilities for doing this are broken and mangle the CentOS iso images and remove the UEFI support from them. Use dd to copy the iso image or use the Windows rawrite utility that's linked off our http://wiki.centos.org/HowTos/InstallFromUSBkey page.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke

NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/03/03 17:15:10

I'm using a DVD, the full CentOs 7 install.

I'm not using a USB stick.

NP77
Posts: 7
Joined: 2018/02/25 14:08:21

Re: Problems with CentOS 7 and Windows 7 Dualboot

Post by NP77 » 2018/03/04 21:01:41

My dualboot is working now, thank you for your help.

I used a LiveDVD for CentOs 7 I burned a while ago, I dont know exactly when. The installation went smoothly, no problems with my keyboard and mouse.

The full DVD I burned recently I tossed it away. Even though the check integrity DVD option I did after booting from the DVD worked out fine.

After following the steps posted by owl102 the dualboot worked fine.

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