I’m getting really confused with my EE Core Install, I would appreciate any help…

I have tried to install EE Core several times; I get to page 4 of the install process, enter the relevant details, click the button and instead of advancing a step/page or confirming the install, it just loops back to the start of the install process! No errors or feedback, it’s like it’s being redirected back to the beginning.

I have used the wizard.php and I get a tick in every box and the db can be accessed fine so I don’t see where the problem could lie.

version is 1.6.4 and I’ve followed the user guide to the letter, read and re-read it.

any ideas?