Not able to access bugzilla.

[shailee]

Hi!!
I have installed the xampp bundle and integrated Bugzilla with test link. I am able to get the bug management icon in the execute page after all the relevent settings and also able to add the bug id but when I tried to access bugzilla through Access to Bug Tracking System (Bugzilla) link or by clicking on the bug id I am getting server error 500
( The server encountered an internal error and was unable to complete your request.
Error message:
couldn't create child process: 720003: show_bug.cgi
If you think this is a server error, please contact the webmaster. ).
I had checked all my settings its fine but cant find out where I am getting wrong.