Hi,
I think you are correct on both accounts.
Down here I don't have the Acronis software installed, but my suspicion was indeed that the service they use to backup the full disk runs under another user account.
Most likely that will be the SYSTEM account. One of the features of the security model in Windows is that a SYSTEM account is not able to access network shares.
You could try to change the user account under which that service runs, but then I don't think it will be able to backup everything you need.
So not sure if there's a way out with Acronis to save to the host/guest file share.
You might try attaching a USB disk directly to the guest? That could work.
Otherwise you would have to find another solution.
Making a manual backup is one way. Using another, in guest backup product, is another one.
As you are talking about windows you might want to look at System backup and see if that works.
Another possible solution is the product I offer: Vimalin. Yep, sorry about playing that (cough cough.. marketing) card, but it appears to fit a bit for what you are asking.
You can make full VM backups with Vimalin. It works for any guest OS and you do not need to install any software into the VM. It uses VMware Workstation snapshot technology so that you don't have to quit the VM, you can add and or edit notes, compress the VM, save to a network share or external disk, schedule backups etcetera...
But you will need a VMware product in order to run the VM once it is restored.
Personally I would think that is not a big problem as you can always download the free VMware Player, but I don't know all your requirements.
For Windows however it means that you don't have to re-activate your VM unless the hardware has changed too much (which in my experience is rare).
--
Wil