Access denied for user 'root'@'localhost'

[Will Barbee]

Why is my access being denied?
mysql -u root -p
Enter password: *********
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)

I installed MySQL 5.7.17 Community on Windows 10.
Used the sequence described in the Ref Manual in 2.11.1 Upgrading MySQL and the section titled Performing a Logical Upgrade. Also followed several cross-references in that section.

1- Reviewed 2.11.1
2- Used MySQLDump to offload my data.
3- Shut down server.
Removed the software using Windows functions. Removed old folders on hard drive.
4- Installed with the MySQL Installer.
5- Skipped initialize data directory. Section 2.3.7 says Installer does it.
6- Start server with mysqld_safe - ERROR mysqld_safe not recognized
So rebooted to start server.
7- Reset root password. The one I set during install was OK, so I skipped this.
8- Reloaded data. All OK. USED THE ROOT PASSWORD HERE.
9- Ran mysql_upgrade. Two messages but all went OK.
10 Shutdown and re-start. Re-booted (as mysqld_safe no good).

Tried to start mysql to define USERS and GRANTS and I got the ACCESS DENIED error.
Why did it work to reload the data and not here? What have I missed?

Thanks,
WillB