When you give the first account a name it asks you to log in with Midrosoft Account. At the bottom of the dialog box is a small blue link that says something like "Don't know this persons details" or Log in with a local account instead" - click that .......
Just use Avast Free BUT don't put any security on until you have updated Windows because it will slow down the setups (See Below). It won't ask you for registration until trial period is up.
Then, bear in mind that the Windows V1903 just came out spend some time forcing updates down it's throat! Even if it tells you the damn thing is upto date Check again LOL
That might take overnight so go for a pint!