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Question HDD only boots when i choose to boot from Usb

May 22, 2020
Everyday i turn on my pc normally and i press F8 to open the Boot menu and choose to boot from my 320 hdd wich has windows 10. But since yesterday it's showing me the error "Bootmgr is missing" So i can't boot from this HDD anymore.

The funny thing is that today i was trying to reinstall windows on this 320 hdd, so i choose to boot from my Usb drive which has a windows 10 installation, but it actually booted from my 320 hdd which was showing the Bootmgr error!

So let me resume: If i choose "Usb Drive" on boot menu, it will actually boot from my 320hdd instead (And i can use windows 10 normally).
But if i choose "320hdd" in boot menu, it will give me the "bootmgr is missing" error. So in order to use my 320 hdd(with windows 10) i need to boot from the Usb Drive :unsure:

And if i unplug the Usb Drive while using Windows, the pc will shutdown instantly, sometimes with a blue screen.

I don't know whats going on! I tried adding a secondary Hdd with windows 7 to see if it will boot normally, but i got an error saying "Disk read error, press Ctrl alt del" so i can't boot from this HDD also! And i know both hdd are good.
Last edited:


May 19, 2020
I think your Bootmgr is damaged, and when you plug in your pendrive with Win10 is using bootmgr from it to boot... your OS from the HDD...

1st thing to do is Boot your windows 10 and check the drive for errors.

After that search in google fix bootmgr... and choose the way most suitable for you to fix it... or Just reinstall the OS, because even if there are ways to fix the bootmgr, they don't always work!