Block visibility using PHP to show Vocabulary and Terms not working In Drupal 6 I used PHP for Block visibility on selected vocabularies and terms. 

The same PHP code does not work in Drupal 7 on a Centos 7 computer. Does PHP 4.4. not work on a PHP 4.5 server? I am using the same examples found here:
https://www.drupal.org/comment/reply/69076#comment-form
Modules written for Drupal 6 are not designed to work with Drupal 7. Some do, by fluke, but it's quite rare. Sounds like you have one of the more common ones, that doesn't.

I'm not sure what you mean by 


  Does php4.4. not work on a php4.5 server?


I think you're confusing several things there, none of which would be related to Drupal.

If you want to know what versions of PHP Drupal supports, see the requirements. If you want to know what version your server supports, your hosting provider will be able to tell you. 

Some modules have specific minimum PHP version requirements; you can find those in the module's .info file, and you'll also be informed in the UI if your system can't support it.