Terminal/Divices/Install Guest Additions
Reboot Terminal
Start your Guest OS in which you want to share drives/folders and files contained in them.
Click on "Devices" tab provided on the VM VirtualBox taskbar and select "Shared Folders" from the drop-down list.
VirtualBox will open a window "Shared Folders". Click on the top icon in the right-hand corner to add the drive/folder. Another window will open—"Add Share".
"Add Share" allows you to give the path of the drive/folder you wish to share from the Host OS by giving the path in "Folder Path". You can also browse the drive/folder from your Host OS if you don't remember the exact path of the contents you want to share.
Now type the name of the folder in the "Folder Name" box. It can be any name you wish to have on Guest OS. Also, check the boxes "Auto Mount" and "Make Permanent" and click "OK".
Go to "Start", select and click "Run" on Guest OS. Type "net use x: \\vboxsrv\Drive F" as the run command and click "OK". If you have done everything alright, then no message or notification will appear. Note that the shared drive/folder name should be the same as given in the "Share Folder" window from Step 6. I gave it "Drive F".