Thanks ArchStant, After nearly an hour and half on the phone to Microsoft, who first tried to convince me that the Outlook problem I had was not to do with the upgrade, and said that the user.000 was the profile I was using, and I should continue to use
it . . . then passed me over to a MS Office specialist who showed me how to create a new Outlook profile etc . . . .
I bit the bullet and rolled back. As you said, perfectly simple and reasonably quick, and Outlook was just back to how I remembered.
They were both puzzled by the fact that my Documents and Pictures etc were not in the profile (which is on an SSD drive), but on my big HD (D:).
I'm still half convinced that the user.000 folder should NOT have been there after the upgrade, as it should be a temp folder while the upgrade progesses, I thought??
I am tempted to try the upgrade once more, after a clean restart or two, sometimes I have found that an upgrade fails, but then will work later . . . And I'm now confident that if it doesn't work a second time, I can rollback. If it works I'll post here.
Thanks for your help on this forum. Strange that the community often finds solutions which MS seem quite oblivious to.