FAO Dark Mantis.. I managed to get a new heat sink & fan. I kept the CMOS battery out for a few days pressed and held the power button for 30secs (as you previously suggested). Removed and reseatted all the jummpers.I then put the motherboard back in the tower, cearfully made sure all connections where good & correct! With just video card, keyboard & mouse attached... NO dvd, HDD or floppy attached! I then booted the tower, went into the BIOS and set to optimized defaults and saved settings..... SUCCESS!! the board booted, showed DMI successfully & stopped at 'insert system disc'. I then installed one drive at a time booting up in-between floppy then HDD then DVD/CD drives. All worked just fine! I have now installed Windows 7 Ultimate. Many thanks to Dark Mantis... Many thanks indeed, please reguard the case as closed.