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WIndows 8.1 "Operating System Not Found" after Fedora21 installation

asked 2015-03-23 00:23:55 -0500

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Dear Fedora People,

I installed Fedora 21 in Legacy mode while i have preinstalled windows 8.1 in UEFI, i installed it in seperate partitino of 50GB raw. When i had to boot Fedora 21 i have to change Legacy Mode in BIOS, it works great, But there is no booting up of Windows 8.1 in both the leagceand UEFI mode. Here is my parted list details.

[root@localhost mfi]# parted -l Model: ATA WDC WD7500BPVX-7 (scsi) Disk /dev/sda: 750GB Sector size (logical/physical): 512B/4096B Partition Table: gpt Disk Flags: pmbr_boot

Number Start End Size File system Name Flags 1 1049kB 1075MB 1074MB ntfs Microsoft recovery partition hidden, diag 2 1075MB 1861MB 786MB fat32 EFI system partition boot, esp 3 1861MB 2063MB 201MB fat32 Microsoft reserved partition msftres 4 2063MB 143GB 141GB ntfs Basic data partition msftdata 7 143GB 143GB 1049kB bios_grub 8 143GB 143GB 524MB ext4 9 143GB 196GB 53.2GB lvm 5 196GB 733GB 537GB ntfs Basic data partition msftdata 6 733GB 750GB 16.3GB ntfs Microsoft recovery partition hidden, diag

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answered 2015-03-23 00:41:20 -0500

cgonz31 gravatar image

updated 2015-03-23 08:38:02 -0500

It is highly unrecommended to boot two OSs from the same disk using two different firmware [UEFI and Legacy (CSM)] modes. Delete all the Fedora partitions and install Fedora in UEFI mode. Take a look at these instructions:

These instructions are for removing Windows 8 but if you ignore the part where he talks about removing the Windows partitions, the rest of the instructions will work for a UEFI dual-boot setup.

You probably can't boot into Windows because your firmware is set to boot in Legacy (CSM) mode while Windows is installed in UEFI mode. If you switch your firmware settings to UEFI booting, you should be able to boot Windows. I can't guarantee that this will work. That's why it's not recommended to boot two OSs from the same disk using two different boot firmware.

If you can't boot into Windows in UEFI mode, you'll have to get creative. Either you reinstall Windows entirely (at which point you should also reinstall Fedora after Windows) or you delete Fedora, change the boot firmware back to UEFI, and use Windows recovery to try to salvage your OS.

I'm not familiar with Windows recovery procedures so I can't help you there.

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I might really messed up, because I installed 32bit fedora with indeed 64Bit UEFI windows partition. Going back to UEFI mode in bios didn't solve the problem. And error remains same. Will try 64bit Fedora so might it work.!

M Fahad Irshad gravatar imageM Fahad Irshad ( 2015-03-23 04:35:35 -0500 )edit

32-bit UEFI booting is NOT supported in Fedora. 64-bit Fedora will definitely work in UEFI.

Most likely you will not be able to boot Windows from GRUB, no matter what boot mode you use.

What I meant was for you to switch to UEFI mode in the firmware and try booting Windows from the UEFI boot menu. This is accessed by pressing a key at POST. The key varies between OEMs but it's usually either ESC or one of the "F" keys.

Since you installed Fedora in Legacy (CSM) mode, then Windows should be the only OS in the UEFI boot menu.

cgonz31 gravatar imagecgonz31 ( 2015-03-23 08:43:41 -0500 )edit

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Asked: 2015-03-23 00:23:55 -0500

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Last updated: Mar 23 '15