When i want to instal profiler... i see:

Hello, i don't know why.. but profiler is not installed.

http://www.busimatch.com/administration/modules.php

When i want install it, i see:

Duplicate entry '_bx_profiler' for key 'Key'

What can i do please? 

 RE

 Do you understand the purpose of that module?

Profiler is for debugging purposes, and also requires a manual file change to work (as explained in the installation's conclusion notes). Unless you need to use it, it doesn't need to be installed. It's not for profiles.

Was the module previously installed? Check its install.sql file and make sure none of those entries are in your database.

Profiler is standard for Dolphin i suppose.
Yes, before it was installed i think.

Unless you need to check how much memory is being used on a page, or how many SQL queries were fired, it shouldn't be installed.

In that case, check its install.sql file and then make sure all those entries were deleted from the database, then clear cache.