[?]: Software for mitsubishi

[PLC_ITA]

good morning friends, i'm novice of mitsubishi. For now i don't need a software and i haven't idea which software i need.
My customer ask to me if is possible to do a little modification into machine equpid whit mitsubishi plc.
My customer remember "melsoft" . i dont know the version. I have only a backup.
The machine is 3 years old.
I have search but any link are expired or do not work. Anyone can help me ?

1: how can i do to know which version i need ?
2: where i can find a mitsubishi software

thank you in advance

[PLC_ITA]

sorry .... my english is very poor

2 : where i can find a mitsubishi software ?