How to copy data from a working hard drive from a computer that does not have Windows?

Question

System administration

The situation is as follows:
1. There is a laptop without Windows
2. There is data inside the laptop 3. There is
an external disk of 4 terabytes, one is busy
How to overwrite data from under Windows without deleting data from an external disk nothing. Tell me the utility, pliz.

Answer 1

Any Windows-live (there are plenty of torrents).
Or any Linux distribution in Live mode.