MSI 7071 mobo w P4 640 win XP home new install. Was playing with overclocking options. Boot failed so cleared CMOS After that started hanging up on boot "boot device not detected..." So checked the BIOS aok Ran UBCD seagate tools HDD OK Repair console: chhdsk; mbrfix; bootcfg /rebuild; Fixboot Didn't work so repair installed windows. Problem recurred!! tried again fixmbr etc etc NOTHING WORKS But interestingly if I leave the xp cd in the drive and allow the boot to proceed, (ie dont "click any key to boot from CD") XP boots from the HDD no problem. To my mind >> mbr or similar issue...have any of you guys you had a similar case? Any suggestions? Or am I at the nuclear option: complete reinstall? Much obliged if you can offer any help.