Windows 10: "Remove disks or other media" appears when I try to boot to USB

Before you ask

I have an Acer Aspire E14 that is running Windows 10 version 1809.

I am trying to boot to my USB, because I want to go back (clean install) to Windows 7.

1 month has passed, so I cannot downgrade.

The issue

So I booted to BIOS and switched my boot order to make the USB first and my HDD second. I also disabled UEFI boot and set it to Legacy.

When I saved my changes I restarted and it showed me a black screen with "Remove disks or other media". I removed my bootable USB flash drive but it said I need to put it in and press any key again. I did that, and it said "Remove disks or other media" again. It just kept looping.

What I did

Restored the boot order, and set it back to UEFI, and just booted back into 10.

:)

 

Installation media boots to command prompt

I've just booted from known working install media to see exactly what it does when booting. The sequence of events is...

1. Windows logo on a black screen
2. circling dots appear beneath the logo
3. light blue 'Please wait' screen with circling dots
4. a command prompt window (very briefly)
5. the initial Setup page appears

Do you see steps 1-3? If so, it appears you have stopped at step 4, suggesting that something on the disc cannot be read.

Does the disc boot properly in another machine? If so, try cleaning the laptop's drive lens then try booting from the disc again.

If not, make new install media with Microsoft's Media Creation Tool, either as a bootable USB, on an ISO that you can burn to another disc. At Step 8 in Option One of this tutorial you can choose between making a USB or an ISO.

Download Windows 10 ISO File

 

Disk boot failure after removing old Vista partition

Thank you for the reply, muchomurka! As I indicated in my post, I have already tried all the steps you suggested to no avail:

- I cannot choose startup repair since the computer does not boot from the installation media
- I cannot use command prompt since the computer does not boot further than the POST screen
- I have disconnected and tried out all hard drives individually.

Since I had Win 10 up and running a few hours ago, I can say with 100% certainty that none of the hardware is faulty.

The real mystery is, how come the system won't boot from any media without an empty disk containing an old Vista boot sector being on top of the boot priority list? And which steps to take now that I've cleaned this disk and it does not exist anymore?

Would appreciate any ideas and pointers!

 

Installing windows off of a USB stick

Step By Step from vista:
From admin cmd prompt

1. diskpart
1a. list disk
2. select disk 1 (replace 1 with your usb drive)
3. clean
4. create partition primary
5. select partition 1 (replace 1 with your usb drive)
6. active
7. format fs=fat32
8. assign
9. exit

Copy Windows Vista's DVD ROM content to the Flash Drive

xcopy d:\*.* /s/e/f e:\ (d being your vista cd and e being your usb stick)

And that's it, boot off your usb disk