Here is some background. I had a 1TB HDD with Windows inside it. Partitions something like this:I bought an another hard drive of 2TB and wanted to dedicate 1TB to Windows and another to Linux. Here is a screenshot of the second hard drive.As you can see, sda2 had Windows bootloader at time of installing CentOS 7. I intentionally tried to install CentOS bootloader (i.e. grub?) in first hard drive so that CentOS can detect it. But seems like CentOS couldn't detect Windows even after that. Here's my output from fdisk -l if screenshot is not enough:WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes, 3907029168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesDisk label type: gpt#         Start          End    Size  Type            Name 1           34       262177    128M  Microsoft reser Microsoft reserved partitionPartition 1 does not start on physical sector boundary. 2       264192   1953646591  931.5G  Microsoft basic Basic data partition 3   1953646592   1955743743      1G  Microsoft basic  4   1955743744   3907028991  930.5G  Linux LVM       WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.Disk /dev/sda: 1000.2 GB, 1000204886016 bytes, 1953525168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesDisk label type: gpt#         Start          End    Size  Type            Name 1         2048       616447    300M  Windows recover Basic data partition 2       616448       819199     99M  EFI System      EFI system partition 3       819200      1081343    128M  Microsoft reser Microsoft reserved partition 4      1081344   1048575999  499.5G  Microsoft basic Basic data partition 5   1048576000   1887436799    400G  Microsoft basic Basic data partition 6   1887436800   1953521663   31.5G  Microsoft basic Basic data partition 7   1953521664   1953523711      1M  BIOS boot parti Disk /dev/mapper/cl-01: 981.9 GB, 981873983488 bytes, 1917722624 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesDisk /dev/mapper/cl-00: 17.2 GB, 17179869184 bytes, 33554432 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesDisk /dev/mapper/luks-13bc4611-477c-4df5-bfb7-b2bbd696e18b: 981.9 GB, 981871886336 bytes, 1917718528 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesI researched a bit and found that I can do update-grub command. But that here is not possible. CentOS 7 uses different grub than Ubuntu's grub (correct me if I am wrong).I also found a grub2-mkconfig method, but this command doesn't finds Windows bootloader:Generating grub configuration file ...Found linux image: /boot/vmlinuz-3.10.0-514.26.2.el7.x86_64Found initrd image: /boot/initramfs-3.10.0-514.26.2.el7.x86_64.imgFound linux image: /boot/vmlinuz-3.10.0-514.el7.x86_64Found initrd image: /boot/initramfs-3.10.0-514.el7.x86_64.imgFound linux image: /boot/vmlinuz-0-rescue-fd2ff737d87642cc87d59785cf5f2390Found initrd image: /boot/initramfs-0-rescue-fd2ff737d87642cc87d59785cf5f2390.imgdoneThis is a UEFI capable computer.I made a discovery, found this:Is this of any use?
How to get Windows on grub menu? Using two HDDs; Windows bootloader on first
centos;windows;grub2;uefi;grub legacy