You may encounter the following:
>net start mysql The MySql service is starting. The MySql service could not be started. A system error has occurred. System error 1067 has occurred. The process terminated unexpectedly.
Check that basedir and datadir in configuration file my.cnf are pointing to the correct directories. They can be muddled due to an old installation.
Disable DNS lookups as a faulty DNS server can cause slow connections as mysql reverse and forward looks up the IPs that are being connected. You can disable it using the --skip-name-resolve option.
Depending on the size of your server (memory, cpu, disk etc..), MySQL comes with recommended settings. Look into these instead of installing the defaults.