The uploaded file exceeds the upload_max_filesize directive in php.ini. (Solution)
If you got that message when you are trying to install for example any plugin like WP e-Commerce which weigh about 3,5 mb in WordPress:
The uploaded file exceeds the upload_max_filesize directive in php.ini.
Just create .htaccess file in your wordpress folder in my case is:
and add the following code inside:
php_value upload_max_filesize 50M
php_value post_max_size 50M
php_value max_execution_time 500
php_value max_input_time 500
and save the file.
Thats was the solution in my case.