Where did you change this parameter?
It should be as the manual says in _ProgramData_ and not in Program Files (x86) \. .\my.ini
"The default configuration file my.ini in the data path for the MySQL server determines the functions
and performance of the MySQL server. The default data path for the my.ini file is
C:\ProgramData\MySQL\MySQL Server 5.5."
You can verify if the parameter was actually changed within MySQL:
C:\>mysql -u root -p
Enter password: ********
Welcome to the MySQL monitor. Commands end with ; or \g.
[...snip...]
mysql> select @@max_connections;
+-------------------+
| @@max_connections |
+-------------------+
| 400 | <<<
+-------------------+
1 row in set (0.00 sec)
mysql>
Please be careful and don't copy/paste the parameter. Find it in my.ini and change it.