There is a common problem in PrestaShop. Right after installation of fresh new PrestaShop store, you try to go to your admin page, and all you see is undescriptive 500 error page. But don't rush to remove store, and write angry comments on forums. Let's try this solutions first:
DISCLAIMER: Before making any changes, don't forget about BACKUP!
- Enter you admin folder on server and delete .htaccess file.
- Make sure that all files and folders has right permissions (755 - for folders, 644 - for files).
- Turn on debug mode, and if instead of blunt 500 error page you'll see page with more explicit info, search for that problem.