WIN 2K does not recognize 250 GB HD

I HAVE A 250 GB HD WITH WIN 2000 INSTALLED ON IT. I UPGRADED THE BIOS AND STILL ONLY READS 20 GB HD. IF I VIEW INFO UNDER ACCESSORIES, SYSTEM TOOLS, SYSTEM INFORMATION, COMPONENTS, STORAGE, AND DRIVES, IT READS THE DRIVE SIZE OF 250 GB, BUT THE FREE SPACE AND SIZE ONLY ADD UP TO 20 GB. IN ADDITION, I REVIEWED THE REGISTRY TO MAKE SURE IT READ EnableBigLba DWORD 0x1.
HOW DO I MAKE THIS OPERATING SYSTEM RECOGNIZE THE ENTIRE HD? HELP PLEASE