note 84040 deleted from faq.installation by googleguy

Note Submitter: jonas at carello dot se ---- If after installting/upgrading PHP on Windows 2000/2003/2008 server with IIS, you're only getting blank pages (or if examining the headers, HTTP 500 errors), try the following: 1. Uninstall PHP and remove all traces of it, IIS ISAPI settings, php.ini and the entire PHP directory. 2. Restart the computer. 3. Install PHP again, you can install and use extensions if you wish. 4. Check the ISAPI settings in IIS (or CGI, depending on what you're using). 5. Restart IIS several times (don't ask me why, it makes no sense). 6. If it still doesn't work, copy the following files to %WINDIR%\system32\ from your PHP directory. (Some files might not exist, I think it depends on your choice of extensions.) libmysql.dll (if you're using MySQL) libeay32.dll (even if you're not using OpenSSL) ssleay32.dll (even if you're not using OpenSSL) libmcrypt.dll (If you're using mcrypt) libmhash.dll (If you're using mhash) 7. Restart IIS again. 8. If it still doesn't work, check if you have additional lib*.dll in your PHP folder and try copying these to %WINDIR%\system32\. The above has helped me 3 times when updating my PHP installation (first from 5.05->5.1.4, second from 5.1.4->5.2.1 and today from 5.2.1->5.2.6). Each time I've run into the exact same problem, blank pages (500 internal server error). I hope this helps someone.