Thanks so much!
Sorry, this is a long overview.
I have five systems, four of which I now have on Windows 10 and one of those went via 8.1.
They all have/had their own problems with upgrading, although the majority of the problems seem to be with video card vendors being unable to get their video drivers correct.
One system was a brand new 7 that I upgraded straight away and that has very few problems but that had a nVidia GTX960 card.
One is a two year old I5 Acer laptop with Intel Graphics and the b*st*rds don't even support an upgrade to 10. Having done it though, anyway, I get the occasional hang and blue screen.
The other two are Core 2 Duo's and had nVidia GT340 and GT740 cards. I have upgraded them to a GTX750 and a K620 (had to have a low profile) hoping that a more modern card would resolve the driver problems.
The GTX750 seems to be ok now from a video point of view but I can't type anything at the Win key.
The one with the K620 (a Core 2 Duo HP6000) still has video driver problems, hanging for no apparent reason, requiring a hard boot, but the worst thing has been the non-functioning start menus.
The hard drive, with 7, originated in another HP system where a service guy fried the motherboard. I had so many problems with it when I moved it to this other system due to the fact that MS wouldn't certify it. Eventually that was resolved and I updated to 8.1. However, I wasn't able to access many of the system functions.
It has three users...
One was presumably setup by the original vendor. One I setup for myself but I was not able to access Windows Live Mail so, from a forum suggestion, I set up a third user and that was fine for accessing Live Mail.
In 10, the third user was not able to pull up programs by typing at Start. The second user could pull up programs but couldn't execute them. The original user was fine.
On a forum suggestion, I downloaded your tweaking program. I ran it for third user and it resolved their problems. I didn't realise that I had to do it for individual users but, as the problem remained for the second user, I ran it for them and that resolved their problem.
Anyway, thanks again for resolving my problems. Now I will run it on the other Core 2 Duo system to see if it resolves the problem there.