That’s almost certainly due to a PHP error, and errors are not being shown in the browser on your host. I suspect something in config.php is amiss. Can you post the config.php, or look for these common errors:
- strings must be quoted (like your akismet key if you entered one)
- your domain name, home and siteurl must all be quoted (due to slashes and colon)
- possible problem with the table prefix for bb or wp?
If you have a command line at your host, you can also check the syntax of the config.php file by running:
php -l config.php
No syntax errors detected in config.php
that’s a lowercase L after the php
Post your config (edit out the good stuff) if you need more help.
Create a file called test.php and put in it
<?php
phpinfo();
?>
If you get a huge page with something on it with loads of information then you have windows installed. Just looking at your 404 pages show that you have a windows server – low change of having php more likely to be asp.