Early Windows 11 builds had notorious issues with Intel RST (Rapid Storage Technology) drivers. Fujitsu released patched drivers within two weeks of Windows 11 GA, preventing the dreaded "INACCESSIBLE_BOOT_DEVICE" error that plagued Lenovo and Asus users.
A: Check the "Lifecycle" page on Fujitsu Support. Look for "Windows 11 Ready" status. Models from 2018 onward (M.2 SSD, UEFI BIOS) are almost always ready.