Unable to install WordPress on Plesk Control Panel (Windows Server)
when you are trying to install the WordPress using Plesk 12.5 on Windows server platform and you are getting an error
‘mysql’ is not recognized as an internal or external command,
operable program or batch file.
The cause of error
WordPress ToolKit bug with id #EXTWPTOOLK-326. The fix is considered to be included in further Plesk updates.
Fix the Error
To work around the bugs and fix the error you just need to locate the location of windows.php and replace the %plesk_dir%\admin\plib\modules\wp-toolkit\library\Capability\Windows.php file with Attached Fixed File one.
Reference support.plesk.com