There is vast improvement in situation at the moment, computer is no longer crashing or shutting down, but still little sluggish and has temporary freezes. I definitely feel this is a driver conflict scenario and not hardware, however have little experience in knowing which or what other driver is the problem.
After your last I message I took following steps
1 un-installed nvida drivers.
2 took card back out machine.
3 rebooted and let on-board graphics boot up.
4 disabled and un-installed on-board graphics.
5 shut down computer and replaced graphics card.
6 Let windows update auto assign driver for car and ignored cd driver I received with purchase.
This has improved the situation and I feel I am nearly there, half of the problems have gone. I could not do a full windows restore as I am still hunting down my reboot cd.
I have few more question I hope you can help with. In device manager I notice on-board, video, sound and game controller. notice this is assigned to Realtex high declination audio. Shouldn't this be controlled by my new graphics card? Could this be another conflicting program? Should I disable or un-install this program and let my graphics card run it?
Thanks for your patience your advice has been very much appreciated.