Please help me! Ubuntu won't boot

[miqe21]

Everytime my computer boots it says: Default Boot Device Missing or Boot Failed. Insert recovery media and hit any key then select boot manager to choose a new boot device or to boot recovery media. When i insert the usb i have with ubuntu on it all i can do is access command prompt, try ubuntu, or install ubuntu. And the only boot option my computer gives me after that error screen is Grub64 and it doesn't work at all. What should I do???????

[yancek]

The first thing to do would be to post some information. For example, how new/old is the computer? Do you have any other OS installed on it? Is it the newer UEFI or the older MBR? Details on manufacturer and hardware to start.

[miqe21]

I have an acer aspire one cloudbook 14. It came with Windows 10 then I installed another Linux Distros by the name of Deepin incorrectly because i totally lost Windows 10. It has the older MBR and 32 GB of eMMC, Intel Celeron Processor N3050, AND 2 GB DDR3 L MEMORY.

[miqe21]

I was trying to toally remove the Deepin OS and replace it with Ubuntu now I can't access anything