Hi. Maybe the next advice will help somebody, some day. I had ,for repair, a Amilo L 6825. I had to make a fresh windows xp profesional sp3 installation. The bios was the last verison from website - 1.07C. I reseted the bios settings to "optimal default" but when I tried to install the windows , I get the " Stop : C0000221 Unknown Hard Error; a corrupted \SystemRoot\System32\ntdll.dll " . I fixed the problem by disabling, inside the bios, under HDD tab, " 32-bit transfer support" . After that, the installation went well. Good luck.