This dll's are OCI.dll, libcs.dll and maybe some other...
Well, going through Google a lot of good meant tips and tricks are named but they all compiled do help - finally.
Therefore, if you get an FastCGI- or similiar error message first try to test whether PHP does work from the console. Simply open it and run it via php-cgi (if you created a phpinfo.php on your inetpub root). Maybe you want to try it with php-cgi phpinfo.php.
Usually you'll get the mentioned error called:
*.dll was not found, for example: OCI.dll was not found, libcs.dll was not found ...
Well, that's easy to handle - if you know what todo.
a) OCI.dll is related to Oracle stuff - therefore, if you don't need it just open you php.ini and outcomment everything that is related to Oracle and extension - I mean EVERYTHING :)
b) libcs.dll is related to Symantic - so do the likewise to a) with Symantec related extensions.
And here we go. Everything works fine.
BTW: If you are using an 64bit system, the whole thing does work perfectly here as well.
If you find that the whole thing doesn't work at all, adding HKEY_LOCAL_MACHINE/SOFTWARE/Wow6432Node/PHP a string value called IniFilePath with the path to your PHP installation does do the thing. Under a 32bit system, you find the PHP- Entry below SOFTWARE :)