Nothing happens when I click on "Configure Firewall"

I've been using Sophos since v7 and now using Sophos Endpoint Security with AV v 9.5.1 and CF 2.5.0 on a Windows XP SP3 PC.

It's been working fine for several weeks until last night when I uninstalled Nero v9.

During the uninstall I got a pop up from Sophos saying that  firewall had been set to allow all traffic.

Tried to click on configure firewall to re-enable it and nothing happens, no error, no egg timer and no pop up.  There are no errors in any of the windows event logs

Even though the message said it had been set to allow all traffic I have no network access unless I stop the CF service.

So I uninstalled Sophos completely, rebooted, removed folders and regkeys left behind and tried a reinstall.

Same thing happens.

I have run a complete AV scan, with no result.

All the other links in the Sophos Endpoint Security and Control window work fine, including the Firewall log, just not the Configure Firewall.

I thought that it may be corrupt config but surely the uninstall would have fixed it.

Any ideas ?