Fatal error: Call to undefined function drupal requirements url() in /install.core.inc on line 738

Hi I have tried installing new drupal version using GoDaddy.

I have a template theme which I have bought from TemplateMonster.com. I have followed the guidelines of installing a them using a demo profile. I have called the intall.php file -> selected English -> Then an error. Fatal error: Call to undefined function drupal requirements url() in /install.core.inc on line 738

I really have no idea what it means or how to deal with it. I have noticed some people have advised changing the max_execution time in database.inc but I can not find the line of code that pertains to.

Any help would be gratefully recieved,
Thanks,
Harry