Have you activated sh404SEF®? When installation has been successfully completed, the component is not activated by default, as it is better you have a chance to review its basic settings before your site URL change.
Go the sh404SEF® control panel using the sh404SEF® entry in Joomla Component menu. There, click on the Configuration button (first left button). The first entry you will see on the configuration screen is:
Enabled ? (probably currently set to No)
Set this to Yes, and click on the Save button. You will be prompted to Erase the URL cache. Click on OK, and sh404SEF® should be activated now. You need to visit your site front-page, so that your new SEF URL are created. If your site is multiligual, you should read Multilingual sites.
Assistance with technical questions, product inquiries and customer service can be found in our 