Windows Upgrade Help and more

Same here. And just to double-check, is Secure Boot also enabled in the BIOS, as that's another common requirement? Hope that helps.

First, don't panic—this is a common issue. Windows updates often overwrite the bootloader. To get GRUB back, you'll need to boot from a Linux live USB and reinstall GRUB to your main drive. After that, you can use a tool like EasyBCD in Windows to add a Linux entry back to the Windows boot menu ...