Dual- and multi-booting with Windows 10 is often a fragile thing. And I seem to encounter many cases where NVMe and eMMC drives have problems with Linux. I personally have current problems with eMMC, so I want to be very cautious that you do not make this situation worse such that you lose access to any of the OS'es since they are all working for you. The need to "press a key continue" is only a slightly annoying delay and not really a serious "problem."
To me, it is quite unusual to see an error like "no server" before any OS has started... and therefore no networking is yet enabled. Some motherboards have the ability to use ethernet so they can easily update the system BIOS. A couple of things to try:
1. Connect the Dell to your router with an ethernet cable and then boot it up. Does the error go away?
2. Go into your BIOS settings and explore every section... looking for anything that might need internet connectivity. If you find something that does, can you disable it?
Google isn't giving much information on this. If the things above don't help, can you take a photo of the error and post it here? There may be a clue in some of the text shown as the GRUB process runs, and just before the error.