OK, I am not programmer(perhaps "repairer") - it was just an attempt This sample is not applicable only due to size restrictions - work only on FAT12 mode with max FAT12 limit 32MB. Extended functions(defrag,scandisk,format...) are not necessary here - it's a ramdisk(after reboot is content deletet) When switch it to FAT16 mode(need code repair),this extend the size to max 4GB (64k x 64k) and this may be applicable ---------- Yes, I know, that there are a lot of other functional solutions,but original XP ramdisk.sys is not sample. Why does not work and why is implemented to XP install CD, when is not working?