Question Bootable USB - - "An operating system wasn't found . . . . ." ?

[Nndrei]

Hello everyone.
First of all, thank you for your time.

I have a PC that had Windows 10, I installed Ubuntu on it. And now I would like to reinstall Windows 10, but I have problems.
I have created a bootable USB from my MacOS laptop and formatted the USB to FAT, FAT32....

But whenever I try to boot the PC from the USB I get this error:
"An operating system wasn't found. Try disconnecting any drives that don't contain an operating system.
Press any key to restart"

I put the usb first in the boot order, I've changed and tried "Legacy Only" and "UEFI Only"....,
read my bios manual and I haven't seen anything that can help me.
I don't know what else I can do.

My bios is B450 AORUS PRO
Bios version: F64a

Can anyone tell me any solution since I have been having this problem for weeks?

 

[RealBeast]

I would start out by using the bios tool to secure erase your OS drive and then use a USB stick with a W10 installer on it to do the new install. You may also need to clear the CMOS.

 

[Nndrei]

I would start out by using the bios tool to secure erase your OS drive and then use a USB stick with a W10 installer on it to do the new install. You may also need to clear the CMOS.

Hey, thanks for your answer. Do you know some tutorials for this? Because I have no idea about how to do it.

Ok, clear the CMOS is just remove the battery. But secure erase your OS drive, no idea.

 

[TerryLaze]

But secure erase your OS drive, no idea.

Don't do it, your problem is the usb drive not being recognized, wiping your os drive will just make your PC not boot up into ubuntu either so it will be useless until you would be able to fix this.
If you followed a link to make the usb stick in macos then link that so we know what exactly you did, otherwise explain it as best you can.
If your bios is set for secure boot you have to also reset the keys for it to boot to a new secure medium.
If you are familiar with wine on macos run rufus and try making an usb with that.

 

[Nndrei]

Don't do it, your problem is the usb drive not being recognized, wiping your os drive will just make your PC not boot up into ubuntu either so it will be useless until you would be able to fix this.
If you followed a link to make the usb stick in macos then link that so we know what exactly you did, otherwise explain it as best you can.
If your bios is set for secure boot you have to also reset the keys for it to boot to a new secure medium.
If you are familiar with wine on macos run rufus and try making an usb with that.

Hey, thanks for your answer.
This is the tutorial:

View: https://www.youtube.com/watch?v=4-HjtRrzk64

(Short video 6mins)

 

[TerryLaze]

Hey, thanks for your answer.
This is the tutorial:

View: https://www.youtube.com/watch?v=4-HjtRrzk64

(Short video 6mins)

Yeah this will only work if the USB is already prepared to be bootable which not all of them are.
You have to treat a USB the same as a hard drive and make an active partition on it for it to be bootable.
So try some different USB drives or follow a guide on how to properly active partition a usb drive.

Create a bootable USB flash drive

Learn how to create a bootable USB flash drive to use to deploy Windows Server Essentials.

learn.microsoft.com

Be very careful, if you select a wrong drive you can kill your main OS.
The important part here is this command 'create partition primary' which will make a bootable partition.

Only do the stuff without the sources folder, that should get the USB booting if the USB is bootable, if it does boot then you can start working on the sources folder.

Also I don't know if the split file thing will work.

 

[Nndrei]

Yeah this will only work if the USB is already prepared to be bootable which not all of them are.
You have to treat a USB the same as a hard drive and make an active partition on it for it to be bootable.
So try some different USB drives or follow a guide on how to properly active partition a usb drive.

Create a bootable USB flash drive

Learn how to create a bootable USB flash drive to use to deploy Windows Server Essentials.

learn.microsoft.com

Be very careful, if you select a wrong drive you can kill your main OS.
The important part here is this command 'create partition primary' which will make a bootable partition.

Only do the stuff without the sources folder, that should get the USB booting if the USB is bootable, if it does boot then you can start working on the sources folder.

Also I don't know if the split file thing will work.

Hello, thanks for your reply and sorry for the late answer.

I'm creating the booteable USB from my MacOs Laptop and I can't follow that tutorial.

 

[CountMike]

Hello, thanks for your reply and sorry for the late answer.

I'm creating the booteable USB from my MacOs Laptop and I can't follow that tutorial.

For W10 you don't need to do much. Just a Fat32 formatted USB stick and copy contents of Windows 10 ISO to it.
Note. I said CONTENTS not just ISO file.Should be able to mount ISO (as virtual disk) on Mac or Linux-

 

[Nndrei]

For W10 you don't need to do much. Just a Fat32 formatted USB stick and copy contents of Windows 10 ISO to it.
Note. I said CONTENTS not just ISO file.Should be able to mount ISO (as virtual disk) on Mac or Linux-

It's not like that.
You need to do several things.
First you can't just paste the content of the ISO inside the usb, because there is a too big file, named ./sources/install.swm
So you have to split it into install.swm and install1.swm.
Then you must make sure that the usb is marked as bootable usb (I think this is my problem and I don't know how to change it).

So it is not that easy to create a bootable usb on macos =/

 

[TerryLaze]

So it is not that easy to create a bootable usb on macos =/

The problem is there aren't many MacOs users here, I think.
In general any partition software is able to create a primary partition on an USB drive, the trouble is I have no idea what partition software there is on macos.

 

[borris618]

Try go into the bootmenu and choose the usb from there instead of having it as first priority in the bios.
Its probably f9 while starting up.
I have had a similar problem where i couldn't boot from usb when selecting it in bios, but choosing it from bootmenu worked just fine somehow.