I have a 6g Wd hard drive that was installed on an old P166. It was installed with EZ-Bios for compatibitly with that system. I am now trying to install that drive in a PII 300. The Bios finds the hard drive 3 out of 5 times when booting, but I get a primary hard disk fail error. I have used WDs newest lifeguard tools, it states that EZ-Bios is not installed on the drive. It also states that the BIOS is not controlling the HD properly. I have tried to enter user settings in the BIOS with the original settings that the drive had when functioning and also the settings that WD states are the proper settings niether makes a difference. I ran diagnostics and it states that the drive is good and I never had any difficulty before moving the drive. Fdisk states no fixed disks present even when the BIOS finds it. WD lifeguard gives me an error when trying to reformat the drive. The error is backing up of new boot track failed, and error initializing drive parameters. I tried using a low level formatter that I have used on many drives before and gives a divide error. When using WD lifeguard it states that the current sectors are 0 when they should be 125….. I am almost positive that it is unable to initialize due to the previous mode (CHS) of the drive. I slaved the drive and booted into a working system, the BIOS found the drive, but Windows did not display it. I have been working on this for three days and I am out of optins and help will be greatly rewarded.