Before Ubuntu installation the drive had one NTFS partition with data. I used windows software to shrink the NTFS partition and create 2 more unformatted partitions for ubuntu installation.
At this point I made a backup of the MBR using windows.
Since then, files have been added / changed on the NTFS partition but the partitions stayed the same size and no other partition was created.
In removing GRUB so to make disk unbootable (If I just erase ubuntu system, I still get a GRUB message at boot - if the disk is 1st in queue), IS IT SAFE for my NTFS files to replace the MBR with the one I have saved???
Thanks
bootrec /fixmbr
(as described here) is the safer method. – MadMike Nov 15 '13 at 06:55