I was a regular user of magento 1 month before but now i found difficult to install the magento. Magento is not installing in localhost neither in XAMPP nor in WAMP all the versions and keep on showing the following error:

There has been an error processing your request

Exception printing is disabled by default for security reasons.

Error log record number: 142520047

I have tried all the setting options that are present on all the support forums. Please someone help me in finding the solution.

These are the errors in report

a:5:{i:0;s:193:"Error in file: "C:\wamp\www\magento\app\code\core\Mage\Api2\sql\api2_setup\install-1.0.0.0.php" - SQLSTATE[42S01]: Base table or view already exists: 1050 La table 'api2_acl_role' existe déjà";i:1;s:912:"#0 C:\wamp\www\magento\app\code\core\Mage\Core\Model\Resource\Setup.php(645): Mage::exception('Mage_Core', 'Error in file: ...')
#1 C:\wamp\www\magento\app\code\core\Mage\Core\Model\Resource\Setup.php(421): Mage_Core_Model_Resource_Setup->_modifyResourceDb('install', '', '1.0.0.0')
#2 C:\wamp\www\magento\app\code\core\Mage\Core\Model\Resource\Setup.php(327): Mage_Core_Model_Resource_Setup->_installResourceDb('1.0.0.0')
#3 C:\wamp\www\magento\app\code\core\Mage\Core\Model\Resource\Setup.php(235): Mage_Core_Model_Resource_Setup->applyUpdates()
#4 C:\wamp\www\magento\app\code\core\Mage\Core\Model\App.php(417): Mage_Core_Model_Resource_Setup::applyAllUpdates()
#5 C:\wamp\www\magento\app\code\core\Mage\Core\Model\App.php(343): Mage_Core_Model_App->_initModules()
#6 C:\wamp\www\magento\app\Mage.php(683): Mage_Core_Model_App->run(Array)
#7 C:\wamp\www\magento\index.php(87): Mage::run('', 'store')
#8 {main}";s:3:"url";s:44:"/magento/index.php/install/wizard/installDb/";s:11:"script_name";s:18:"/magento/index.php";s:4:"skin";s:7:"default";}