WordPress not working under PHP 5.4

I am having trouble getting WordPress to work under PHP version 5.4

More specifics would be most helpful. Errors? Warnings?

Have you tried temporarily deactivating ALL of your plugins and/or your theme to rule out those conflicts?

since v5.4 PHP is using mysqlnd to access mysql, prior versions defaulted to mysqlclient library, when SQL password is using old (MYSQL v4) hash it will not work with mysqlnd (which supports new hashes only)
Password issue usually happens for old installations.

When it does not work for you – have you checked error logs? Do they show any error?

The logs do show an error.

[17-Jun-2013 16:27:41 America/Tegucigalpa] PHP Fatal error: Call to undefined function wp() in E:\wwwww\xxxxx\yyyyy.com\http\wp-blog-header.php on line 14

Its generic error, says thats scripts were not properly loaded and it seems that some file is broken, can be a syntax error or not closed tag in wp-config.php or any other script file improperly uploaded to host

btw do you have long file names with spaces in your path? I dont have much experience with IIS but for PHP its better to keep paths short and without spaces.
Thus, PHP has dropped support for old Windows versions recently, you can try using 5.3, its not yet EOL

I do not have spaces in any file paths. My Windows version is 2008 RC2.

I’ve tried PHP 4.3.5, 5.4.14, and 5.4.16. No luck.

Did you ever get this figured out?