I am reinstalling Windoe XP on a Dell Vostro 1510 laptop. I have a full XP disk (that Ihave used many times before) and I have tried three different Sata hard disks in the laptop. I have even tried a newly formatted one. However XP comes up and says that there are no hard disks installed in the laptop - even tho 'it has benn recognised in the BIOS - What is happening??