I'm going to try and break this down so it's a little easier for people to understand!
My problem: I currently work for a charity that houses vulnerable adults who require internet access for various reasons. Due to the nature of this clientele, any computer use must be monitored at all times to ensure they aren't using the computer for inappropriate purposes.
The computer that will be monitored is an old Pentium 4 DELL running Xubuntu which automatically logs into a user on our Windows 2008 R2 server when turned on. This is currently working perfectly with absolutely no issues at all.
It is running X11VNC server, and I am able to connect to it successfully with programs such as MRemoteNG and the TightVNC client on Windows machines.
My solution: The answer to this is I believe to be a Raspberry Pi B+ that automatically connects to the X11VNC server on the DELL on boot. Therefore negating any human interaction going forward which is perfect for my colleagues as they aren't as computer savvy.
My technical issue: I have previously tried Remmina and xtightvncviewer on the RPi B+ to connect to the X11VNC server, having absolutely no success with the xtightvncviewer and minor success with Remmina which appears to connect after authenticated, and then disconnects instantly after.
I'm a tad stuck on what to do here, as I don't seem to have any alternatives going forward apart from perhaps trying another RPi distribution.
Any help is greatly appreciated in advance.