To access folders in Virtualbox with Windows XP as the guest system, you have to jump through a some of hoops, but it really isn’t that hard.
First, setup the folders you want to share via
Devices > Shared Folders in Virtualbox.
Next, in your Windows XP Virtual Host, close all of your Windows Explorer windows. Then press the Windows Key and the E key to open a tree view version of Windows Explorer.
Don’t click on My Network Places! Expand it instead. You should see
Entire Network. Expand that.
You should now see Microsoft Windows Network and VirtualBox Shared Folders. Feel free to click on VirtualBox Shared Folders, or continue to expand down the tree until you see your folders.
It’ll be a bit slow, but it should work. If you think you’ll be doing this a lot, you should be able to right click on
\\Vboxsrv and use the Create Shortcut choice to send a shortcut to your desktop.
I hope this helps you access your shared folder.