is simply going to create 3 nodes with no properties, and thus a node with label :File a node with label :Process and a node with label :Registry. .... and I suspect this is not what you want.
Maybe you want something similar to
CALL apoc.load.json('processes.json') YIELD value AS processes UNWIND processes AS Process
CREATE(p:Process) set p.image=Process.Image,
p.processguid=Process.ProcessGuid,
p.processid=Process.processid
p.utctime=Process.UtcTime;
CALL apoc.load.json('files.json') YIELD value AS files UNWIND files AS File
CREATE(f:File) set f........
CALL apoc.load.json('registry.json') YIELD value AS registries UNWIND registries AS Registry
CREATE(r:Registry) set r........
note the references above and on line 8 and 10 and to set f........ and set r........ would need to be further defined by you