Do you have Linux or anything else installed? cause this happens when the bootsector is corrupt or overwritten by another OS.Track 0 Sector 0 is your MBR (Master Boot Record) which holds your partition and tells your BIOS how to Boot your System in Windows 9x (IO.Sys) in Windows NT or 2000 (NTLDR) the best way to clear your MBR is to boot in DOS and at the prompt type SYS C: and this will copy IO.sys to the hard drive and then go ahead and install Windows 2000