Unable to setup MariaDb on Windows

• I am unable to get MariaDb running on my Windows development machine
• I've tried the MSI installer, mysql_install_db.exe and mysqld --console.
• I'm running all from an elevated command prompt.
• I have the rights - MySQL Community v8 installer runs fine (without the elevated command prompt) and the resulting mysql service works - but I want to use MariaDb.
• I've installed https://aka.ms/vs/16/release/vc_redist.x64.exe and rebooted my computer

Details

MSI installer - v10.4.13

does the full install but says it can't start the service. Only option is to cancel, which rolls back the install. Screenshot attached.

I then downloaded the zip file to try manually installing. That appears to be v10.4.8

mysql_install_db.exe --datadir=C:\mariadb\db --service=Mariadb --password=xxx

{{Running bootstrap
2020-06-24 9:00:32 0 [Note] C:\mariadb\bin\mysqld.exe (mysqld 10.4.8-MariaDB) starting as process 17272 ...
Removing default user
Setting root password
Creating my.ini file
Registering service 'Mariadb'
FATAL ERROR: CreateService failed (1073)
https://mariadb.com/kb/en/installation-issues-on-windows contains some help
for solving the most common problems. If this doesn't help you, please
leave a comment in the Knowledge Base or file a bug report at
https://jira.mariadb.org}}

mysqld --console

{{2020-06-24 8:31:20 0 [Note] mysqld (mysqld 10.4.8-MariaDB) starting as process 16216 ...
InnoDB: using atomic writes.
2020-06-24 8:31:20 0 [Note] InnoDB: Mutexes and rw_locks use Windows interlocked functions
2020-06-24 8:31:20 0 [Note] InnoDB: Uses event mutexes
2020-06-24 8:31:20 0 [Note] InnoDB: Compressed tables use zlib 1.2.11
2020-06-24 8:31:20 0 [Note] InnoDB: Number of pools: 1
2020-06-24 8:31:20 0 [Note] InnoDB: Using SSE2 crc32 instructions
2020-06-24 8:31:20 0 [Note] InnoDB: Initializing buffer pool, total size = 128M, instances = 1, chunk size = 128M
2020-06-24 8:31:20 0 [Note] InnoDB: Completed initialization of buffer pool
2020-06-24 8:31:20 0 [Note] InnoDB: 128 out of 128 rollback segments are active.
2020-06-24 8:31:20 0 [Note] InnoDB: Creating shared tablespace for temporary tables
2020-06-24 8:31:20 0 [Note] InnoDB: Setting file '.\ibtmp1' size to 12 MB. Physically writing the file full; Please wait ...
2020-06-24 8:31:20 0 [Note] InnoDB: File '.\ibtmp1' size is now 12 MB.
2020-06-24 8:31:20 0 [Note] InnoDB: Waiting for purge to start
2020-06-24 8:31:20 0 [Note] InnoDB: 10.4.8 started; log sequence number 113856; transaction id 9
2020-06-24 8:31:20 0 [Note] InnoDB: Loading buffer pool(s) from C:\mariadb\data\ib_buffer_pool
2020-06-24 8:31:20 0 [Note] Plugin 'FEEDBACK' is disabled.
2020-06-24 8:31:20 0 [Note] InnoDB: Buffer pool(s) load completed at 200624 8:31:20
2020-06-24 8:31:20 0 [ERROR] Could not open mysql.plugin table. Some plugins may be not loaded
2020-06-24 8:31:20 0 [ERROR] Can't open and lock privilege tables: Table 'mysql.servers' doesn't exist
2020-06-24 8:31:20 0 [Note] Server socket created on IP: '::'.
2020-06-24 8:31:20 0 [ERROR] Fatal error: Can't open and lock privilege tables: Table 'mysql.db' doesn't exist
2020-06-24 8:31:20 0 [ERROR] Aborting}}