The error you are getting now is telling you that the include files cannot be found in the location specified in the link. Rite now it is looking for the files here:
../../WA_SecurityAssist/Helper_PHP.php
Based on the location of the file that is giving you this error:
C:\xampp\htdocs\test_hills25\webassist\email\mail_ php.php
It would be looking for this file in
C:\xampp\htdocs\test_hills25\WA_SecurityAssist\Helper_PHP.php
Do you have these files in this location? If you find these files in your site and make sure they are in this location you should not get these errors.