Can't share folders OS X host, windows XP guest

[WDB]

Host = OS X El Capitan
Guest = Windows XP pro 32 bit SP3
Virtual Box installed and running
Windows XP installed and running
Guest additions successfully installed (I think - it said installation was successful)

With Windows XP not running (state = saved):
Settings
Shared folders
folder with green +
folder path = other
folder path = users/davidbutts/documents/autocad drawings
read only and auto mount buttons not checked
OK
path shows under "machine folders" - access = full
OK
error message = failed to save settings,The machine is not mutable or running (state is Saved).

Result Code:
VBOX_E_INVALID_VM_STATE (0x80BB0002)
Component:
SessionMachine
Interface:
IMachine {85cd948e-a71f-4289-281e-0ca7ad48cd89}

Failed to save the settings of the virtual machine Windows XP to /Users/davidbutts/VirtualBox VMs/Windows XP/Windows XP.vbox.

With windows XP running, devices menu/shared folders shows the path under "transient folders", but I can't open the folder (nothing to click on).
If I hover over the dialog box, a yellow box appears saying in part "...use "net use x:\\vboxsvr\share" to access a shared folder named share from a DOS-like OS..." I don't know what this means, or how to do it.

Thanks for your help...
WDB

[ChipMcK]

my approach is as follows:

1. Boot up windows vm
2. Start (my) Computer
3. Select Tools from Menu Bar
4. Select 'Map Network Drive ...'
5. follow prompts

Before the above will work, you need to define the Shared Folder(s) in VBox according to your host implementation

[socratis]

failed to save settings,The machine is not mutable or running (state is Saved).

You cannot make changes while the VM is in "Saved state". You need to completely shutdown the guest, from within the guest.

It's similar to a computer that's hibernating. You wouldn't change the amount of RAM, the CPU, or any other "hardware" features, would you? Same concept...

[WDB]

ChipMck: Thank you! Worked like a charm - chalk this one up a "solved".
socratis: Thank you as well. I didn't try your method because I got ChipMck's method to work first, but I really appreciate all your help.
WDB

[socratis]

I didn't try your method because I got ChipMck's method to work first

Just remember that the next time you reboot your guest. If the changes aren't permanent (in the Settings), they're going to be lost...