PHP4 and PHP5 w/ IIS6.0, Win Server 2003 (HKEY_LOCAL_MACHINE\...\IniFilePath vs. PATH vs. PHPRC) concurrent installation

Greetings, I've been looking all over for an answer to this predicament... seamless installation of PHP4 and PHP5 in the same machine... My environment: Windows Enterprise Server 2003 IIS6.0 PHP3.8.9 PHP5.0.1 MYSQL4.0.20d MS SQL2000 I would like to create a nice integration development environment in the same machine that supports IIS -> PHP -> (Mysql or MSSQL) in the same server I've had a very hard time getting PHP4 and PHP5 running concurrently. The closest that I was able to get it was to Unpack all php 4 into c:\httpd\php4 copy all files from c:\httpd\php4\sapi\* and dll\* into c:httpd\php4 directory (i.e. move up one directory) Unpack all php 5 into c:\httpd\php5 Set the administration PATH env variable to PATH=...;c:\httpd\php5\;c:\httpd\php4 Go to IIS -> Web Service Extensions - > Add New Extension (1) for PHP pointing to c:\httpd\php4\php4isapi.dll and (2) for PHP5 pointing to c:\httpd\php5\php5isapi.dll Go to IIS -> Web Sites -> [Properties] -> Home Directory -> Configuration... -> add mappings .php5 to php5isapi.dll and .php to php5isapi.dll edit php.ini-recommended on each directory (i.e. php4 and php5) only uncommented several dynamic extensions and, cgi.force_redirect = 0, and extension_dir = "c:\httpd\[php4 | php5]\ext\" Cold boot While I can get both php to respond correctly, I cannot see any dynamic extensions loaded. Qustions: Under the above arrangement which php.ini is being use for php5? At one point I deleted php.ini and it made no difference. I have opted to set PHPRC = c:\httpd\php5 which does ready the php.ini and loads my extension correctly. However I break php4. What to do? Many thanks for any insight into this... Orlando