this part of install.txt which is came with zip file :
To do this, you should move php4ts.dll to the windows/system (for Windows 9x/Me)
or winnt/system32 (for Windows NT/2000/XP) directory, overwriting any
older file. Then you should add the following three lines to your Apache
conf file: (swap c:/php/ for your PHP install path)
LoadModule php4_module c:/php/sapi/php4apache.dll
AddModule mod_php4.c
AddType application/x-httpd-php .php
If you wish to install PHP as a CGI binary, (the sapi is much better)
you need to enable the apache security fix in your php.ini by
setting cgi.force_redirect = 1. Then, insert these lines to your conf file: