1) Comment out the addtype lines in the php5.conf file and the php4.conf file.
And in the /etc/apache2.conf I put this but must this stay soo when I install ispconfig?
No, please comment this out.
3a) If you want to enable php5 in a website, enable the php checkbox in ISPConfig for this website.
3b) If you want to enable php4 for the website, make sure that the php checkbox and the cgi checkbox are not enabled. Then add the following lines in the aoache directives field:
AddHandler php-script .php
Action php-script /cgi-bin/php4
Now all files ending with .php are executed by php4 and not php5.