Need some help...
 
Have two dives original pata 80GB and new SATA 500gb
 
Vista and ubuntu both on new second dive
 
have a working dual boot system with vista and ubuntu hardy heron everything works fine except that if I remove the original disk or change boot order in bios the bootloader (grub or Vista ) doesn't load.
 
I want to reformat original drive to use as data backup

hmm,
Maybe 80GB's disk got the 'right' MBR that points to the Linux boot partition.
So, you may try to copy the 1st drive's MBR to the second.
 
So now, the 500GB drive's MBR will point to the good 'file'.
 
Have you try that ?

Solved problem by disconnecting 80GB drive and then bootinq VISTA Disk and repairing faulty install After three tries repair worked now have booting system off SATA drive and Scean 80GB drive. Thanks for pointer I think you were right as to MBR on 1St DRIVE