Files not opening up on local instance of Box

I have a user that cannot always open files that have not been looked or updated in a long time. She said it just spins but never opens. She can however open an older file online and that works just fine. She thinks Box is not syncing which maybe the case because she has almost 120GB of data that is syncing to the local hard drive which at best has maybe 90GB which I would say is less. I am sure that Box does not sync 120GB of data every time right? If the file be old Box would have to find it and sync the request is made hence spinning like it wants to open and maybe the can also attributed to a wireless connection that makes it slower right.