I have a Windows 10 host running VirtualBox, and I have a Windows 7 guest os. I wanted to get files from the Windows 10 box through to the Windows 7 box. This can be done using Shared Folders if you have the guest additions installed.

In the VirtualBox window, choose Devices/Shared Folders/Shared Folders Settings...

In here, click the folder + on the right hand side to create a new entry. In the folder path, put the folder on your host OS you want to share. Give it a name in the folder name box. For my example, I used:

• Folder Path: c:tmp
• Folder Name: tmp

Once this is done, you can assign a drive letter to the share, using:

net use t: \\vboxsvr\tmp

Your c:tmp folder on the host is now accessible in the guest os as drive letter t: