Thank you for the helpful input, some items I have done and others to try.
1/ Power supply I reckon is OK as when I get the rastered screen the previous page is still there in the back ground. But will keep that on my check list. I will connect a voltage stabiliser I have in stock for one thousand watts.
2/ CC Cleaner is used a few times a week on registry and cleanout. I set the warnings for temperatures lower than the defaults.
3/ I will go to the Gigabyte site for updates. When the CPU was changed new thermal paste was used as a new fan was fitted at that time.
4/ Device manager says all drivers are OK. Ref the BIOS, it opened itself up tonight so I set a larger memory for the internal video. It was 64 MB and now 128 MB.
Event Viewer may be the Reliability Monitor, in Win 10. Not much info in that just ‘your confuser shut down unexpectedly’.
Once again thanks for the input, I will check these answers out.