how to upgrade from php3 to php4

Dear newsgroup, I am a complete php newbie, and I wish for your consideration. I got a little problem here - I can't upgrade my php3 to php4: could you give me a step by step instructions on how to upgrade from php v3.0.17 to v4.1.2? I followed instructions found on the web - configured the httpd-conf and restarted the apache web server. But, when i tried to execute the phpinfo() function (a code in a file named test.php, of course), all I can see is a blank page. What i did on the httpd-conf is the following: a. put the line ScriptAlias /php4/ "C:/php4/php-4.1.2-win32/" b. put the line AddType application/x-httpd-php .php c. adn put the line Action application/x-httpd-php4 "/php4/php-4.1.2-win32/php.exe" and saved it. Then copied the php4ts.dll and msvcrt on my winnt\system directory. Also, I renamed the file php.ini-dist to php.ini and copied (and overwrite) it to the winnt directory. Then after, i test the configuration (that is, start>program files>apache http server>configure apache server>test configuration) and find no errors. And finally, I restarted apache... but when i entered the url http://localhost:8000/php/test.php, i get a blank page... :( Why is it so? please help... I really really need your help... I cant sleep with this simple problem bugging me... Thank you very much for your kindness and time. sincerely, ryan