Windows 10: "No Bootable Device"

Hi There ,Yesterday I put my windows at hibernate mode for 2 hours.When I reopened it , a screen appeared showing "No Bootable Device".I turned off my laptop and turned on again but it was still showing.I clicked F2 and entered a menu where I switched to Legacy mode.And it worked , my laptop was booting again but I noticed that the booting became slower .I tried to change it back to UEFI but it showed the error again so I am stuck with Legacy mode.Help I want to put it UEFI mode as it first was because the booting in Legacy is taking more time.Note: I don't have a Windows Disc installer.

:)

 

Multi-bootable USB

Hey guys from TPU, couldn't find any specific thread pertaining to the question asked on title. As mentioned, I'm trying to create a bootable USB, but with many specifics boots available.

I've been trying to create one with multiple boot device including one that enables me to run Windows 10 directly on the USB Thumb Drive but to no avail.

The list of bootable images i'm trying to create are

1. Windows 10 (A full OS running from thumb drive)
2. Windows 10 ISO (Bootable disk image for fresh install)
3. MemTest86+

Have tried YUMI or UUI from the website USB PenDrive Linux but as this is my first time, i don't know how am i screwing up or am doing it right.. Anyone got a rough idea on a step by step guide? Thanks!

 

Ipod bootable drive?

I want to know if I can make my ipod a usb bootable drive.. will it mess up my ipod? I need to flash my video card back to normal.. Neros bootable cd gave me an error. I used a step by step guide, but thats another story.

 

Bootable device not found

computer is not booting a black screen come
up with this message bootable device not found i have properly attached my all cables even then my bios show that sata ports empty no hdd found