Old Windows PC to Apple Desktop

My parents have had a windows PC for decades now and their external drive for the PC is irreplaceable. Their entire system now is all Apple products (homes, iPads etc) and I really wanna set them up with the simplicity of an Apple home based computer. Is there a way to join their existing drive (I believe it runs windows 10, and they keep getting reminders that windows 10 is going soon and support from Microsoft is gone!) to an Apple desk top?

i Know sometimes hard drives are not compatible between windows and Apple and I would hate for them to lose everything on the drive.