Run system command from PHP

I am trying to modify the registry by running a *.reg dynamically created by PHP. I am having trouble gettting the file to execute from within PHP. I actually create a *.reg file and save it. I then try to run it from PHP. I've tried using exec, system, shell_exec() and none seem to actually work. I don't get an error message either. When I run the *.reg file from a cmd window, it works fine. I also noticed that it prompts the user once and then confirms the change using some alert box mechanism (windows builtin). Is there anyway to do this? -- Gerardo S. Rojas mailto: grojas@strategicinc.com