First check this option in Product option
Solution 1 : Manage Products > Select All, then select the action Update Attributes and add the products to the correct website(s).
Left side Display this information :
Products Information
Attributes
Inventory
Websites <-- select this option
And select Main website under the Add Product To Websites
Don't forget to rebuild the indexes.
Solution 2 :
- are enabled
- have stock quantity > 0
- have stock availability = In Stock
- have visibility = "Catalog, search"
- have the correct website assigned to them
- have the right tax class associated with them
Solution 1 : Manage Products > Select All, then select the action Update Attributes and add the products to the correct website(s).
Left side Display this information :
Products Information
Attributes
Inventory
Websites <-- select this option
And select Main website under the Add Product To Websites
Don't forget to rebuild the indexes.
Solution 2 :
<?php
require_once('app/Mage.php');
umask(0);
Mage::app('admin');
$website_ids = array(1, 2); // I'm assuming your website IDs are 1 and 2.
$product_collection = Mage::getModel('catalog/product')->getCollection();
foreach($product_collection as $product) {
$product->setWebsiteIds($website_ids);
$product->save();
}?> 
