Unusual problem with booting on a Windows-only PC running Linux.
Unusual problem with booting on a Windows-only PC running Linux.
You're dealing with a Windows PC that hasn't run Linux before. It's using a 4TB NVMe drive for booting and a smaller SATA 2TB drive for games. After locking it in and powering it off, you tried to discharge the battery by holding the power button for 20 seconds before rebooting. When you got back into Windows, you saw a GRUB menu that kept showing up. This happened repeatedly until you managed to access a Linux partition alongside your Windows setup. It sounds like your system is trying to boot into Linux, but there might be some issues with the boot process or power management settings.
You're using a GRUB screen in a restricted mode. It might be a text-based interface with a console. Enter EXIT to access the bootloader. This issue is happening on both Windows 10 and Linux Mint.
I can answer why it defaulted to Grub. Your NVMe probably experinced a bad sector that was replaced with a healthy one. The data copied from the bad sector probably had an error when referencing the EFI boot partition and your system tried to find one and found the Ubuntu partition first. As for why there was an Ubuntu partition on your NVMe... I got nothing. I doubt there is a way for it to appear out of nowhere and I don't know any malware installing Ubuntu on a Windows system. Merry Xmas !