Thanks for your assistance.

Nortons does still leave a lot of 'stuff' (that I could easily identify) even when using the Nortons Removal Tool -but nothing that looked like any drivers. May still have been stuff in the Registry. Didn't touch the registry but cleaned out what other stuff I saw.

Fridat night to Saturday morning. Same problem, decided to do a another clean install Saturday.

Saturday night to overnight 'cold' restart on Sunday morning. Installed Win7 Pro, MSE and all of Gigabyte's (from their disk) hardware drives and some utility drivers (ET6, DMI View, and Update Mgr, and Win's 23 inportant updates and 13 optional updates. Sunday morning very much the same problem except that the BSOD indicates a Stop:00000007E problem (no file name mentioned). Only problen is ET6 will not start again?

Tripple checked that the nemory (GSkill) was on the approved list and inserted in the correct slots - everything ok seemingly. New Seagate 1TB (unallocated) used to setup.

Sunday night to Monday morning's cold start. Installed Win7 Pro, MSE and 3 updates from MS, did not install any of Gigabytes hardware or software (drivers). Monday morning (today) very similar problem however I was unable to see what was on the BSOF as is flashed past too quickly. There was no Minidump directory or ntblog file (this may have been started from me enabling in previous installations).

This may still be a Win7 problem but is looking increasingly like a hardware problem. I did see an inconclusive post on a forum about the GSkill (F3-12800CL9D-4GBNQ) despite being on the approved list for the AMD MB (Gigabyte 790FXTA-UD5) it is targeted towards Intel CPU's and is a possible problem on an AMD board. Another suggested a problem between CPU (AMD Phenom II X4 965) and the GSkill that mainly resided with how AMD's CPU's handle a particular process and that it was not the memory that was at fault.

Strange that Win7 will start/restart straight away or withing a couple of hours but will not start if left overnight or for as yet uncertain longer time (never tested thoroughly to try to identify what is the time period for this)?

I had emailed (a couple of days ago) Gigabyte about ET6 not starting they said it was a issue with installation (online newer download over the original DVD version) and to reinstall. However as can be seen from today's failure to start, that was not the problem as no Gigabyte software was installed and the problem remains.

Darn! If more light can be shed I would be thankful?
Looks like I am over to the Gigabyte and hardware forums. Suggestions on which are the better boards to help from here would also be appreciated.

Kind regards Trevor