I am describing again what had happened: I followed carefully the instruction of the new MB and assembled what I had on the old MB. After confirmation of very pieces again, I switched on the power, POST was OK and I was able to get into BIOS manu by pressing the Del key. After the POST, however, a message apreared saying 'In valid system disk, plaese remove it from the drive and hit any key' and the machine stops there not going any more... I made a trial boot using a set of 4 disks made from Win2000 CD as suggestted by Barry in previous message. This time I was allowed to install the Win2000 but the resulting OS did not work in full functionally with mouse failed and monitor worked in limited resolution (not sure other windows functionalities).
