[ubuntu_studio] What is taking up so much space? To Delete or not Delete a Snapshot?

Confused about this issue:

Looking at a second HDD with nothing but a WinXP VM thereon, via Properties it shows;

-----------------------------------
24 items, totalling 116.6 GB
(some contents unreadable)
17.7 GB of 141.5 GB free
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When looking in the folder: /Data/VirtualBox VMs/XP32-1/Snapshots/, I see two Snapshots. Can I delete the old one?
One is dated today 42GB, and the other 11.21.2016 at 31GB.

My question is, what is taking up all the room? Besides WinXP, all I'm running therein is MetaStock (trading system).
Don't remember it ever taking up that much room. Concerned about running out of space! I could delete the WinRE on this HDD,
but that would only clear up approx. 14 more GB.

Sorry, this probably should be in Virtualization ... unsure!
Thanks!
Rick