Click https://www.centennialsoftwaresolutions.com/blog/enable-copy-paste-between-windows-7-and-ubuntu-16-04-3-on-oracle-vm-virtualbox to enable copy/paste and folder sharing between Windows 7 and Ubuntu 16.03.4 running on Oracle VM VirtualBox Version 5.2.12 r122591.
Reference
VirtualBox logo from [link].