OK I had the last straw tonight.
Although I registered for the upgrade, I wanted to do it in my own time. But no, it was done straight away.
Since the upgrade, any restart takes 5 minutes while it does a pre boot scan. W7 loaded in 1 minute, no trouble.
Then, Paypal wouldnt accept my debit card yesterday, details were ok, it just kept telling me the card details were incorrectly entered, so somehow the protocols were being mishandled, or misinterpreted. Abandoned that.
Took some photos today, but every time I wanted to open a viewer to look at them, I was getting a popup asking me if I wanted to do it with a brand new Microsoft app, which of course would need paying for, or the same old boring Windows Photo Viewer which of course I had paid for when I bought Windows 7 Ultimate for £250.
This afternoon I wanted to access my internet banking site, normally whenever I do this I will run a Malwarebytes scan just to be on the safe side.
Clicked on the icon, up came the UAC which I approved, only to be told that 'this application could not start'. In other words, I was running without protection, but hadnt been notified. My Malwarebytes is the pro verson with active shields, but obviously if it couldnt start, the shields would be useless.
What a pile of poo. Rolled back to W7. Everything works properly now.