I have a dell inspiron 15 7000 series note book. I had win 10 installed in it. Due to some reason i planned to reinstall win 10. So i changed the boot setting from UEFI to legacy and then i deleted whole of my hard disk and then i installed win 10. During the installation an error message is shown again and again as " this disk is GPT partitionized. The some how after many tries i completed installing windows. And now when i restarted my lap after changing the boot option again to UEFI it says no boot device found. But win 10 runs when i change the boot option back to legacy. But i want to run windows by keeping the boot option as UEFI. what should i do? Some one please help me

  • 1
    switch bios to uefi and reinstall windows 10. – Moab Jan 15 '16 at 16:01
  • But when i switch bios to uefi and try to install Windows pc says no bootable device found – Ampatishan Arun Jan 15 '16 at 16:04
  • Generally Windows in UEFI needs GPT HDD and when in Legacy it’s compatible with MBR HDD for installation. If your disk is currently MBR convert it to GPT, set UEFI Mode in firmware setup and try installing Windows if you wish to use UEFI mode. – patkim Jan 15 '16 at 16:12
  • Possible duplicate of Windows 10 Can't Install from USB Disk to UEFI – phuclv Aug 25 '18 at 1:04

Yes, you can't have your cake and eat it. You either install win10 in bios mode or UEFI mode, after which you can't switch, since bios mode uses MBR (old) and UEFI mode uses GPT (EFI partition).

as the posters say, best (and more modern) bet is to set bios to UEFI and reinstall from scratch


  • How can i install windows 10 again in uefi – Ampatishan Arun Jan 15 '16 at 16:29
  • many ways to do it. quick and dirty: borrow a windows machine, download the latest iso using the media creation tool (google for link). get a spare USB stick (8GB min). Install rufus. open rufus, set GPT and FAT32, and point it to your iso. When done, reboot. set bios to UEFI, and select your stick. It will take you to the (EFI) installer. Pingers. – Pingers Jan 15 '16 at 16:31
  • Since now also it says no bootable device found – Ampatishan Arun Jan 15 '16 at 17:24
  • It's possible to switch from MBR to GPT without reinstalling. How can I migrate a Windows 10 from BIOS/MBR boot to UEFI/GPT without reinstalling?. The reverse way is also possible although trickier. And it's incorrect to say bios mode uses MBR (old) and UEFI mode uses GPT (EFI partition). BIOS doesn't care whatever partition type you have, therefore you can install Linux on a GPT disk. GPT can also boot from MBR as long as there's an ESP on the drive – phuclv Aug 25 '18 at 0:59

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