This happens because XP doesn't have drivers for your modern SATA/NVMe controller.
menuentry "Windows XP (Legacy via UEFI-CSM-less chainload)" insmod part_gpt insmod ntfs insmod chain set root=(hd0,gpt3) chainloader +1 install windows xp on uefi system exclusive
To understand the difficulty, one must first grasp the root of the conflict. Windows XP was designed for the Basic Input/Output System (BIOS) firmware, which uses Master Boot Record (MBR) disk partitioning and a 16-bit real-mode interrupt system to boot. UEFI, by contrast, mandates the GUID Partition Table (GPT) and boots via EFI executables ( .efi files) stored on a dedicated FAT32 partition. XP’s bootloader, ntldr , cannot read GPT disks, cannot launch EFI applications, and cannot initiate a boot sequence without legacy BIOS interrupts (INT 13h). A standard installation attempt on a UEFI motherboard will fail immediately: the installer will either not detect any hard drive, blue-screen with error 0x0000007B (inaccessible boot device), or refuse to launch altogether. Therefore, an "exclusive" installation—one that does not dual-boot with a modern OS—demands a complete circumvention of these architectural barriers. This happens because XP doesn't have drivers for
BSODs. You must "slipstream" (integrate) AHCI drivers into your installation media using tools like Summary Installation Workflow UEFI, by contrast, mandates the GUID Partition Table