Microsoft has fixed a known issue causing “boot device inaccessible” errors during startup on some Windows Server 2025 systems using iSCSI.
“This is observed on servers operating under NDIS Poll Mode booting from an iSCSI LUN,” the company explained when it acknowledged the bug in late October.
“Under such configuration, the server will experience the error during startup, after the installation of Windows Server 2025 is completed.”
The iSCSI protocol (short for Internet Small Computer Systems Interface) is a built-in Windows Server component that allows servers to connect to remote storage devices over TCP/IP networks using SCSI commands.
This allows them to use remote storage (often hosted on a SAN or Storage Area Network) like a local disk, making iSCSI…