How to set up file sharing between a Windows Guest and Linux Host in VirtualBox:

1. First, be sure you have the Windows Guest Addition installed. If you don’t, see the instructions here:
http://www.virtualbox.org/manual/UserManual.html#id2507572

2. Then, set up a shared folder from the Linux side. From your Linux Host, start VirtualBox, then select your Windows Guest OS (just high-light it, don’t start up the OS) in the pane on the left-hand side of the main VB menu. Then click on Settings (the choice along the top left, with the icon that looks like a gear), which will open a new window with several choices along the left side. Choose Shared Folders, which takes you (surprise) to the Shared Folders window. Click on the top icon of the three that appear along the right side – it looks like a folder with a + sign, which will take you to a pop-up window for specifying the Linux folder that you want to share with your Windows Guest. (For example, I chose /home/jim/Documents.) VB automatically assigns it a name that will appear when you see this folder from Windows (sensibly, it chose “Documents,” but I believe you can change this if you wish). If you want to be able to modify – not just view – the files in this folder when accessing them through Windows, then leave the box for “read only” unchecked (the default).

3. Finally, tell your Windows Guest how to see your new shared Linux folder. Start your Windows Guest OS, then open Windows Explorer and look for the shared Linux folder under “My Networking Places” -> “Entire Network” -> “VirtualBox Shared Folders”. By right-clicking on a shared folder and selecting “Map network drive” from the menu that pops up, you can assign a drive letter and name to that shared folder. You can then access your shared Linux folder from Windows. For more details on setting up shared folders, see the discussion in the VirtualBox manual here:

http://www.virtualbox.org/manual/UserManual.html#sharedfolders