To debug the server start process, open a command window, navigate to the bin folder of the mysql installation, and issue this command ...
... substituting for MYSQL_HOME the full path to your mysql installation.
If it fails, you will see error messages. Fix the problems they report. If they befuddle you, post them to the MySQL Newbie forum.
When it succeeds, it will hang, so ...
(i) Stop the server in Task Manager or from another command window with
mysqladmin shutdown
<.pre>
(ii) The command you need for starting the server is therefore
MYSQL_HOME\bin=mysqld --defaults-file="MYSQL_HOME\my.ini"
with the same substitution.