Ok I the pass month I was trying to run php on IIS dedicate Application Pool, the problem was the result show as Error 403. I finally found the solution, and I like to share my finding here with everyone.
As you can see that when install php from the ZIP file. and you run your php extension in IIS DefualtAppPool it work fine. Because the DefualtAppPool run as Network Services. But our dedicate app pool will run as DNPWebUser member group, which doesn't has User Rights Assignment from Windows. The result error 403 when trying to execute the php script.
The solution I found ( anyone please fine tune this)
In Windows Server open Start>Programs>Administive Tools> Local Security Settings
Then browse down to User Policies> User Rights Assignment
Give rights to DNPWebUser by right-click on the rights then choose properties, click Add User or Group > choose Object Types > select only Group - click OK > Choose Advance > Choose Find Now > Select DNPWebUsers group > click OK > click OK > click OK again
Do all this the the following User Rights Assignment.
>Replace a process-level token
>Adjust memory quotas for a process
>Generate security audits
>Log on as a service
Restart IIS, I think you are all good to go.
Good Luck to you all. 
James NW
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