CMD appear and disappear when booting Win10 USB

It seems normal that a CMD appear and disappear when booting from a Win10 DVD made by Microsoft and sold on a DVD media.

But it doesn’t seem normal that a CMD appears and disappears when booting from a Win10 USB or burned DVD created by downloaded files from Microsoft.

In the beginning there didn’t appeared and disappeared any CMD when I booted from a Win10 USB. But after checking my outlook mail, it suddenly appeared. And I expect it to be caused by a rootkit or other type of malicious code. But I’m not totally sure.

I have tried to use PartedMagic NVME Secure Erase to delete all data on my SSD, but the CMD still appears when booting from USB.

If I go to the next page of the installation program and then abort the installation of Win10, the CMD doesn’t appear the next time I boot from the USB. But if I then continue the installation or abort the installation, the CMD appears again the next time I boot from the USB.

I therefore expect the appearance to be caused by a rootkit or other kind of malicious code either on the SSD or on the motherboard. If it was on the USB or other place, I would expect it to appear every time the pc booted from the Win10 USB.

If I’m right in the cause of the appearance of the CMD, I really hope someone can help me get rid of it as I haven’t got any luck with it in about half a year now.

By posting just a description of your problems it is likely that your topic will be passed by and you will not receive the help you're looking for.

We need to know what's running on your computer so we can give you appropriate instructions.

May I draw your attention to THIS topic, which you should have read, and which tells you what we need you to post so that we can help you.

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