Plugin: BackUpWordPress shell_exec() issue
BackUpWordPress is a great plugin for WordPress, but you might get this error sometimes on a windows hosting:
Warning: shell_exec() [function.shell-exec]: Unable to execute ‘which zip’
Here is the solution:
Contacting your host and asking them to enable x shell_exec.
or adding the following to your wp-config.php file should fix the issue.
define( ‘HMBKP_MYSQLDUMP_PATH’, false );
define( ‘HMBKP_ZIP_PATH’, false );