Can't access shared folder with Virtual Box

I have Windows 10 and Virtual Box 5.1.4. I need to create a shared folder which would be shared between Windows and the MSDOS used in Virtual Box. So I used the shared folder option to setup a folder on Windows. The instructions said to then type "net use x \vboxsvr\share" but that gives an error:

C:\Users\eddyq>net use e \\vboxsvr\share
System error 67 has occurred.
The network name cannot be found.

Assuming the "vboxsvr" is to be substituted with the actual host name, I could not find an option in Virtual Box that allows me to type the host name.

So I checked the server list on Windows using Map Network Drive and the server called vboxsf is not there. Searching this forum, I found someone that says there is a group called vboxsf but it is not clear how to use that.

Solution 1:

Install the VirtualBox Guest Additions Plug in.

From Console File → Device → Insert Guess Additions Image CD.

Install and reboot.

Solution 2:

Well, I had the same issue, mounting my host Documents and Pictures folder. Things I did (I cannot regress, if one of them is superficious)

• Install matching Guest Additions again (I did so earlier in setup, well...)

• Hint 1: The .iso can directly be downloaded here (precisely match your virtual box version, as shown in the about menu)

• Hint 2: If you are to lazy to re-add a CD Drive with all the rebooting, you can unpack that iso in your (Ubuntu) Host for example (remove anything x86/OS2/sun... if you like), and drag that folder onto your guest desktop. (Kinda proof that I had pre-existing guest additions, if I think about it. Otherwise, dragging would not be possible). And install the VBoxWindowsAdditions-amd64.exe there.

• Also another nasty problem VirtualBox problem of mine instantly went away. Not related, but kinda proof that some features of GuestAddition can somehow get swept away, perhaps by further Win10 Updates or such.

• I turned off the windows firewall, suddenly I could see my shared drives! (I then turned it on again. Yes, I could still see them. Yes, the old joke...). Since everything is hard to find in Win10 settings, here's what I mean:

Btw: My checkbox on the shared folders look like so:

Btw: Before I had named them Documents and Pictures, perhaps that was too generic and caused trouble, perhaps not.

Well, yeah, reboot, and things work... I could see, work with and permanently map them...