Windows 2000 Professional Corrupted

Hi there,
I have a windows 2000 Professional that it corrupted and i have very important data in there. When i reboot the pc it says “Ntldr missing, press ctrl+alt+del to restart”. Now on Windows 98 you could insert a start up disk and reinstall the os. Here i tried to repair the os by using a ERD floppy disk, Manual and fast repair from windows 2000 pro cd. It seems not to fix it. Anybody has some ideas? Thank you for your help!