Very stupid mistake but can be nightmare for not well advanced people reporting HTTP500 and similar errors on IIS. In last Win32 binary, in php.ini-dist file is a mistype, on the bottom line :

php_mssq70l.dll

where should be:

php_mssql70.dll

maybe would be a good idea to insert short one-line description into README file for this distribution (Win32) saying: if something's not work correctly, try write "php" in the command prompt and see what's the problem...

p.