حل مشكله MySQL Error : Duplicate entry 'subforumdepth' for key 1

Database error in vBulletin 3.8.3:

Invalid SQL:

			INSERT INTO setting
			(varname, grouptitle, value, defaultvalue, datatype, optioncode, displayorder,
			advanced, volatile, validationcode, blacklist, product)
			VALUES
			(
				'forumhomedepth',
				'forumlist',
				'2',
				'2',
				'integer',
				'',
				10,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'forumdisplaydepth',
				'forumlist',
				'2',
				'2',
				'integer',
				'',
				15,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'subforumdepth',
				'forumlist',
				'2',
				'0',
				'integer',
				'',
				20,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'showforumdescription',
				'forumlist',
				'1',
				'1',
				'boolean',
				'yesno',
				25,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'showprivateforums',
				'forumlist',
				'0',
				'0',
				'free',
				'select:piped\r\n0|no\r\n1|yes_hide_post_counts\r\ n2|yes_display_post_counts',
				30,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'showlocks',
				'forumlist',
				'1',
				'',
				'boolean',
				'yesno',
				40,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'lastthreadchars',
				'forumlist',
				'30',
				'30',
				'integer',
				'',
				50,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'showmoderatorcolumn',
				'forumlist',
				'0',
				'',
				'boolean',
				'yesno',
				70,
				0,
				1,
					'',
					0,
					'vbulletin'
	),
	(
				'showprefixlastpost',
				'forumlist',
				'2',
				'2',
				'number',
				'radio:piped\r\n0|no\r\n1|yes_plain_text_version\r \n2|yes_rich_text_version',
				80,
				0,
				1,
					'',
					0,
					'vbulletin'
	);

MySQL Error   : Duplicate entry 'subforumdepth' for key 1
Error Number  : 1062
Request Date  : Sunday, July 5th 2009 @ 04:29:29 PM
Error Date    : Sunday, July 5th 2009 @ 04:29:30 PM
Script        : http://www.Example.com/vb/install/finalupgrade.php?step=1
Referrer      : http://www.wecairo.com/vb2/install/finalupgrade.php
IP Address    : 41.236.254.1
Username      : 
Classname     : vB_Database
MySQL Version : 5.0.81-community

DROP TABLE `setting`

CREATE TABLE IF NOT EXISTS `setting` (
`varname` varchar(100) NOT NULL default '',
`grouptitle` varchar(50) NOT NULL default '',
`value` mediumtext,
`defaultvalue` mediumtext,
`optioncode` mediumtext,
`displayorder` smallint(5) unsigned NOT NULL default '0',
`advanced` smallint(6) NOT NULL default '0',
`volatile` smallint(5) unsigned NOT NULL default '0',
`datatype` enum('free','number','boolean','bitfield','usernam e','integer','posint') NOT NULL default 'free',
`product` varchar(25) NOT NULL default '',
`validationcode` text,
`blacklist` smallint(6) NOT NULL default '0',
PRIMARY KEY (`varname`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1