0x80070035 The network path was not found

Hi
I have a network of 10 windows 8.1 (pro) desktop computers - all identical PCs - all set up about 6 weeks ago.
All computers show on the network. I have one drive mounted on one computer, which is shared with all other computers. I have mapped this drive as I:
All has worked fine until today.
Today one of the computers "FB" has consistently come up with the following error:

0x80070035 The network path was not found.

It also shows An error occurred while reconnecting I: to \\servername\folder

MicrosoftWindowsNetwork: the local device name is already in use.
This connection has not been restored.

All other computers can connect fine.

This computer FB will potentially connect for a short time and then has the above errors. (prior to today it was totally fine).

I have tried resetting the network adapter, switching off firewall, flushing dns.

I have seen lots of similar errors in forums, but no-one seems to have a resolution other than reinstall windows.

Any ideas?
Thanks.