You can always get your copy of the latest stabile version of Magento on the official website:
You can select the latest stable version of the eCommerce system and there are also few very useful tools available too. For example the Magento Sample Data is also available for downloading.
For more instructions on how to install and set up the Sample data – please check this Magneto Tutorial (http://www.magentocommerce.com/knowledge-base/entry/installing-sample-data-archive-for-magento-ce)
If you’re having problems with the download link, try typing it directly into the browser.
Magento download link follows the simple formula:
www.magentocommerce.com/downloads/assets/(put the version number here)/magento-(put the version number here too).zip
Just enter the magento version number in the above url format and everything should work just fine.
Magento version numbers are in format 22.214.171.124 or 126.96.36.199 or 188.8.131.52 etc.
Please remember to login to the magentocommerce.com website as downloads wont work until you do.