is not the same as I:\xampp\htdocs\test
which = http://localhost/test/
being the default server's root directory defined in the xampp\apache\conf\httpd.conf
If you are trying to delete from I:\test ??? and not from http://localhost/test
then the result may be as you indicated above, as you are not going through the server's inbuilt restrictions which are designed to give some level of protection to files and directories outside the server's root - htdocs.
php files should always be called through the server and would be if you gave hosting facilities, not through a directory call by you at your PC as you indicated in your post.
Try and delete the test directory by using a URL in your browser which is as a hosting client would only be able to do, instead of a direct directory call.
If do you want to offer PHP executions for outside persons, please think about a "safe mode" configuration. But for standalone developer we recommend NOT the "safe mode" configuration because some important functions will not working then. More Info
Also do some research using .htaccess.
BTW it is noted on various ApacheFriends web pages and within this forum that there may be security risks in using XAMPP in a production environment as it does not have the Linux enabled web server's level of configurable security.
Having said that even Linux based servers, with all it's security available configurations, is no match for some 'script kiddies' who seem hell bent on reaping havoc for some self indulgent interest.
1. The new DeskTopXampp
launch control for XAMPP / XAMPPlite
Posted by Ridgewood
available from Ridgewood'sDTX web site
2. Make Richer Ajax Applications - Faster
TIBCO General Interface Pro Edition
and Open Source
Fully working with NO
donations required to get a user/password