Load profile from saved profile on old machine
Open to your working bitvise > Click 'Client key manager' > Export > Export private key bitvise format > key in 'export passphrase' (to be use on new machine) > continue > the file read as .bkp
Open bitvise on new machine > load profile ( from old machine) > Click 'client key manager' > import .bkp > change location as per old machine > done