Not sure whether you are running PHP4x as a mdoule or not, but you can run both at the same time.
If you are running PHP as a module, on Apache2, you can try the following. Make a back-up first. Don't use the installer, just get the zip file and unzip all your files to :
C:\PHP\php-5.0.3-Win32.
Then, take a copy of httpd.default.conf and rename it to php5.httpd.conf .
Edit this file accordingly:
# Add the following below the other LoadModule settings
LoadModule php5_module "c:/php/php-5.0.3-Win32/php5apache2.dll"
PHPIniDir "c:/php/php-5.0.3-Win32"
# Check further on if AddType is set for PHP
AddType application/x-httpd-php .php
# Check further on that DirectoryIndex is set up
DirectoryIndex index.php index.html index.html.var
# Listen 12.34.56.78:80 (example) - Change to a different port than httpd.conf
Listen 8000
# PidFile logs/httpd.pid
PidFile logs/php5.httpd.pid
Go to your install directory: C:\PHP\php-5.0.3-Win32 and make a copy of php.ini-recommended, call it php.ini .
Set the extension directory: extension_dir = ".;C:\PHP\php-4.3.10-Win32\extensions"
Go to the command prompt and get to this stage / folder C:\PROGRA~1\APACHE~1\APACHE2\BIN>
Type the following:
apache -k install -n "ApachePHP5" -f "C:\Program Files\Apache Group\Apache2\conf\php5.httpd.conf"
If you have Apache Monitor running, you should now be able to see these 2 services by right clicking the icon in the task bar, and Open Monitor. You can then start your servers. Access your pages by : http://127.0.0.1:8000
