Please take a backup of the database if you have any reusable data in tables.
This is the screen shot after a fresh installation of
Joomla.

After executing the following query , the page will look like this.
Remeber if you had entered any additional data other than default , then it may deleted.
Run the following SQL queries.
TRUNCATE TABLE `
jos_banner`;
TRUNCATE TABLE `
jos_
bannerclient`;
TRUNCATE TABLE `
jos_
bannertrack`;
TRUNCATE TABLE `
jos_categories`;
TRUNCATE TABLE `
jos_content`;
TRUNCATE TABLE `
jos_content_
frontpage`;
TRUNCATE TABLE `
jos_
newsfeeds`;
TRUNCATE TABLE `
jos_polls`;
TRUNCATE TABLE `
jos_poll_data`;
TRUNCATE TABLE `
jos_poll_date`;
TRUNCATE TABLE `
jos_sections`;
TRUNCATE TABLE `
jos_
weblinks`;
TRUNCATE TABLE `
jos_contact_details`;
TRUNCATE TABLE `
jos_menu`;
INSERT INTO `
jos_menu` VALUES (1, '
mainmenu', 'Home', 'home', 'index.
php?option=com_content&view=
frontpage', 'component', 1, 0, 20, 0, 1, 0, '0000-00-00 00:00:00', 0, 0, 0, 3, '
num_leading_articles=1\
nnum_intro_articles=4\
nnum_columns=2\
nnum_links=4\
norderby_
pri=\
norderby_sec=front\
nshow_pagination=2\
nshow_pagination_results=1\
nshow_feed_link=1\
nshow_
noauth=\
nshow_title=\
nlink_titles=\
nshow_intro=\
nshow_section=\
nlink_section=\
nshow_category=\
nlink_category=\
nshow_author=\
nshow_create_date=\
nshow_modify_date=\
nshow_item_navigation=\
nshow_
readmore=\
nshow_vote=\
nshow_icons=\
nshow_
pdf_icon=\
nshow_print_icon=\
nshow_email_icon=\
nshow_hits=\
nfeed_summary=\
npage_title=\
nshow_page_title=1\
npageclass_
sfx=\
nmenu_image=-1\
nsecure=0\n\n', 0, 0, 1);
TRUNCATE TABLE `
jos_modules`;
INSERT INTO `
jos_modules` VALUES (1, 'Main Menu', '', 1, 'left', 0, '0000-00-00 00:00:00', 1, 'mod_
mainmenu', 0, 0, 1, '
menutype=
mainmenu\
nmoduleclass_
sfx=_menu\n', 1, 0, '');
INSERT INTO `
jos_modules` VALUES (2, '
Login', '', 1, '
login', 0, '0000-00-00 00:00:00', 1, 'mod_
login', 0, 0, 1, '', 1, 1, '');
INSERT INTO `
jos_modules` VALUES (3, 'Popular','',3,'
cpanel',0,'0000-00-00 00:00:00',1,'mod_popular',0,2,1,'',0, 1, '');
INSERT INTO `
jos_modules` VALUES (4, 'Recent added Articles','',4,'
cpanel',0,'0000-00-00 00:00:00',1,'mod_latest',0,2,1,'ordering=c_
dsc\
nuser_id=0\
ncache=0\n\n',0, 1, '');
INSERT INTO `
jos_modules` VALUES (5, 'Menu Stats','',5,'
cpanel',0,'0000-00-00 00:00:00',1,'mod_stats',0,2,1,'',0, 1, '');
INSERT INTO `
jos_modules` VALUES (6, 'Unread Messages','',1,'header',0,'0000-00-00 00:00:00',1,'mod_unread',0,2,1,'',1, 1, '');
INSERT INTO `
jos_modules` VALUES (7, 'Online Users','',2,'header',0,'0000-00-00 00:00:00',1,'mod_online',0,2,1,'',1, 1, '');
INSERT INTO `
jos_modules` VALUES (8, 'Toolbar','',1,'toolbar',0,'0000-00-00 00:00:00',1,'mod_toolbar',0,2,1,'',1, 1, '');
INSERT INTO `
jos_modules` VALUES (9, 'Quick Icons','',1,'icon',0,'0000-00-00 00:00:00',1,'mod_
quickicon',0,2,1,'',1,1, '');
INSERT INTO `
jos_modules` VALUES (10, 'Logged in Users','',2,'
cpanel',0,'0000-00-00 00:00:00',1,'mod_logged',0,2,1,'',0,1, '');
INSERT INTO `
jos_modules` VALUES (11, 'Footer', '', 0, 'footer', 0, '0000-00-00 00:00:00', 1, 'mod_footer', 0, 0, 1, '', 1, 1, '');
INSERT INTO `
jos_modules` VALUES (12, 'Admin Menu','', 1,'menu', 0,'0000-00-00 00:00:00', 1,'mod_menu', 0, 2, 1, '', 0, 1, '');
INSERT INTO `
jos_modules` VALUES (13, 'Admin
SubMenu','', 1,'
submenu', 0,'0000-00-00 00:00:00', 1,'mod_
submenu', 0, 2, 1, '', 0, 1, '');
INSERT INTO `
jos_modules` VALUES (14, 'User Status','', 1,'status', 0,'0000-00-00 00:00:00', 1,'mod_status', 0, 2, 1, '', 0, 1, '');
INSERT INTO `
jos_modules` VALUES (15, 'Title','', 1,'title', 0,'0000-00-00 00:00:00', 1,'mod_title', 0, 2, 1, '', 0, 1, '');
TRUNCATE TABLE `
jos_modules_menu`;
INSERT INTO `
jos_modules_menu` VALUES (1,0);
TRUNCATE TABLE `
jos_menu_types`;
INSERT INTO `
jos_menu_types` VALUES (1, '
mainmenu', 'Main Menu', 'The main menu for the site');
TRUNCATE TABLE `
jos_templates_menu`;
# Dumping data for table `
jos_templates_menu`
INSERT INTO `
jos_templates_menu` VALUES ('
rhuk_
milkyway', '0', '0');
INSERT INTO `
jos_templates_menu` VALUES ('
khepri', '0', '1');