I want to know how to make a drive ( non-system ) from EXT4 to NTFS. Can anyone help me out?
If there is enough space on disk,you can first shrink it using any software like gparted and then format it to NTFS.However the best option is Backup-Format-Restore.
As others have said, you would need to back up the data to some other location, reformat your drive as NTFS, then restore the data. There is no way to change from one filesystem type to another without wiping out what's on it at the time.