You can run the command sc delete [MySQL] where [MySQL] is the name of the service.

Explanation

If you take a look at the manual concerning innodb_additional_mem_pool_size you see that this is a configuration variable, which is relevant in combination with innodb_use_sys_malloc. If you take a look at the manual concerning innodb_use_sys_malloc you see that also this configuration variable was marked as deprecated and removed. If you follow the links further to the detailed explanation you can read:

When InnoDB was developed, the memory allocators supplied with operating systems and run-time libraries were often lacking in performance and scalability. [...]

Today, as multi-core systems have become more widely available, and as operating systems have matured, significant improvements have been made in the memory allocators provided with operating systems. New memory allocators perform better and are more scalable than they were in the past. [...]

You can control whether InnoDB uses its own memory allocator or an allocator of the operating system, by setting the value of the system configuration parameter innodb_use_sys_malloc in the MySQL option file [...]. If set to ON or 1 (the default), InnoDB uses the malloc and free functions of the underlying system rather than manage memory pools itself. [...]

Which basically means that this was a configuration variable which makes just no sense to set anymore in modern environments. Therefore it was deprecated and removed and also the innodb_additional_mem_pool_size, which just existed in support of the own memory management.

Fix

Fix for your problem: Remove the corresponding line with innodb_additional_mem_pool_size and (if it even exists) the line with innodb_use_sys_malloc from your my.cnf.