When I installed a new version of Drupal on one of my sites, an error showed up on the administration page:

The status page reports:

Checking phpinfo() showed that Register Globals was "off". This thread on Drupal.org, discusses the fact that even if phpinfo() shows that Register Globals is OFF, this error may still show up, because of a bug in some versions of Drupal.

According to php.net, Register globals can be turned off in .htaccess files like this:

# PHP 4, Apache 2.

<IfModule sapi_apache2.c>

# add the following directive to the list:

  php_flag register_globals                 off

</IfModule>