I can't really catch the meaning of this sentence. It was only given as an example of the use of 统统， I have no more context.
No matter who, after arriving at a new firm, (your ) original files all (will) all be stored in a steel locker, you (can/must/should) start anew.
Or is '铁皮柜‘ some kind of slang for '计算机‘？？
What are '原来档案‘？？