Yeh, windowed mode is a good idea to try - when I get round to it again, I will try one thing at a time so hopefully I will know if any one of the things fixes it.
I never kill applications from the Apps tab, always directly through processes more responsive as you say.
Interestingly (and annoyingly) the game gave me hope when I tried playing a track and then exited the game as it worked.
I played a full single player mission and exited and it did exactly the same thing and died
Every other process in task manager (processes tab) is killable except for explorer.exe and steam.exe
How annoying
Will try posting on the 1C site to see if anyone has any diagnostic type stuff I can run to establish what is happening.
I emailed Steam support about it. They emailed me a link to a page about updating drivers (despite telling them in my email that they are all up to date), brilliant…