how do i enable it?

well, if you are asking yourself that question, the answer is easy..

look in the php.ini file, there you will find information like this:

; - register_globals = Off [Security, Performance]
; Global variables are no longer registered for input data (POST, GET, cookies,
; environment and other server variables). Instead of using $foo, you must use
; you can use $_REQUEST["foo"] (includes any variable that arrives through the
; request, namely, POST, GET and cookie variables), or use one of the specific
; $_GET["foo"], $_POST["foo"], $_COOKIE["foo"] or $_FILES["foo"], depending
; on where the input originates. Also, you can look at the
; import_request_variables() function.
; Note that register_globals is going to be depracated (i.e., turned off by
; default) in the next version of PHP, because it often leads to security bugs.
; Read http://php.net/manual/en/security.registerglobals.php for further
; information.


; You should do your best to write your scripts so that they do not require
; register_globals to be on; Using form variables as globals can easily lead
; to possible security problems, if the code is not very well thought of.
register_globals = Off


as you can see, on my computer register_globals is set to Off, so how do you change the setting?

its simple, just change:

register_globals = Off

to

register_globals = On

save the changes, restart your apache server, and now you should have your register_globals to On

hope this helps