probelm in executing exe from web app

HI

I am calling exe (vb.net application) from web application for this i wrote

code like this

system.diagnosis.process.start("e:\...")

i wrote above code in button click event.

inorder to work this application i made few changes

1. in machine.cinfig file, in <Process Model> entitity i changed on of the

attribute username to "SYSTEM" from machine

2. Administrative tools/services/IIS Admin Services
double click the admin service then in LOgon tab i've checked "Allow Sevices
TO access Desktop"

then stop the service and then start the service.

after making these 2 changes then my application is working.
i've tested this application in windows 2000 professional and it is working

but when am testing the same application windows Server 2003 it is not
executing the exe though i made the 2 chages i said above.

Please Can anubody tell me how to sove this problem.
This is very urgent for me.
Thanx in advance

Kiran