Appreciate all the advice. I tried to give as much background as I could as many of the suggestions unfortunately won’t work for me as I don’t have admin rights (so can’t install Xcode to downgrade the GPTK version, and can’t install via launchcat for the same reason) as Sladester has verified everything worked fine until the GPTK update on my system.
I expect downgrading GPTK will work but I think need admin rights to do that (but will try tonight to check).
as per my original post I’ve tried this with single monitor and dual monitors makes no difference. (fYI before the GPtK update I had it working using either setup single or dual, full screen or windowed. All good).
might have to pop around to the IT guy at work and see if he’s sympathetic (or even better maybe a CoH player :)) and will help me out by letting me install via Launchcat 🙂