Windows 7 Embedded Client Push Image not working

Hello Dell community,

for a few days now I am trying to push an Image on a Windows 7 Embedded 3030 Client.

I tried it with almost every imaging tool (USBFT) version and multiple Windows 7 Embedded versions.

I enable "Boot from USB" in bios and changed the Boot order so that it would boot from the USB.

After that the Client shows "GRUB_" as a text upon booting. In this screen the client I can't change / do anything.