I recently removed XP from my system, leaving Windows 7 Home Premium. I also followed advice here to move my Win 7 partition to the front of the disk. I don't know if that was relevant or not.
Due to this and that now you are getting these issues... I can say with confidence this will b OS corruption.
Could be hardware, and it never hurts to run Hard Drive and Memory Diags, which I do recommend. But, with what you have done to the system,(these things do not always go well unfortunately) this is OS corruption.
If I take an Acronis Image of my system as it is, then full format my C:\Win 7 then restore the image would that be worth doing?
If you take an image of a broken OS,, you have an image of a broken OS. Hope that clears that up.
With regard to the advice to 'repair 7 three times to rewrite the boot file, is there a specific reason it needs to be done 3 times?
Because it will need to repair one thing, then another, then another. Not always needed, but sometimes is.
Currently, I am not happy with this behavior. Something is very wrong here!
Memory tests come up OK each time and a full disk test of C:\was run. When it rebooted it said the volume is clean. I think it did some repairs.
The memory tests should be run for several hours, not just one pass.
The Hard Drive Test you ran was probably CHKDSK which is fine, but it is not a Hard Drive Test.
You will need to find the manufacturer of your Hard Drive and run their tests on it to make sure the HDD is ok.
Please see this Link
for more info on Hardware Testing.