"MySQL server has gone away" when attempting to import a large dump file

My first instinct after reading the error message in the question title was to suggest increasing max_allowed_packet. You mentioned that you tried "that switch" it and it hasn't worked. Can you confirm that you have correctly modified the server's configuration file? Your phrasing makes it sound like you've tried to use that as a command line switch on the mysql.exe client command line, which wouldn't cause the server to alter behavior.

So, in short, what you should try to do is locate and edit the my.cnf file your server is currently using. In the [mysqld] section alter the max_allowed_packet settings to something like

[mysqld]
max_allowed_packet=32M

Don't forget to restart the server after altering the configuration.

I've used 32M (a ridicuously large value) as an example. Since your query seems to be enourmous you should try this value (or perhaps even 64M if you've got enough RAM) to see whether it works.

Another option is to leave the server as-is and alter the behavior of the client used to generate the SQL dump. Tell it to limit the size of the individual queries to under 1 MB - that should also do the trick.

For more details, see B.1.2.10. Packet too large in the MySQL manual.