Can I safely erase my Windows C: partition without breaking Linux?

Don’t manually delete Windows system files one by one. If you’re finished with Windows, back up anything important, confirm the partition you’re targeting with a partitioning tool, and delete or reformat that entire partition. Be especially careful not to select your Linux root, home, swap, or EFI partition. If the goal is to enlarge another partition, the freed space must be adjacent to it, and moving or resizing partitions can take additional steps and carries some risk.

The EFI partition can be on the same physical drive as Windows, but it is a separate partition, so deleting C: normally won’t remove it. Check where your system is booting from before making changes, and keep a bootable Linux recovery USB nearby in case the boot configuration needs repair afterward.

Usually, yes. Linux bootloaders normally live in the EFI System Partition, or in the disk’s boot sector on older BIOS systems—not inside the Windows NTFS C: partition. However, verify which partitions contain your Linux system and EFI files before deleting anything. If the Windows partition is listed in /etc/fstab, remove or update that entry after erasing it, and unmount the partition first.