Crystal Report - Load Report Failed on ASP.Net Page deployed in IIS 7 - Windows Server 2008 x64

Load Report Failed 
Yesterday i got this error, when i'm trying to load my crystal report in production machine. This one is a generic error, it means that, you maybe wondering where this error come from, even i'm wondering too ^^.
Before, in my development machine, everything is fine, i can see the report. 
When i tried to deploy it in my production machine, suddenly this error show up.


This is what i do to solve this problem :
1. Go to IIS -> Application Pools

2. Right click on DefaultAppPool (or application pools that your site using) --> Choose advanced Settings...
If you are thinking How To : Check Application Pools that a site is using from IIS 7, please click the link
3. Choose identity

4.Choose Network Services

5.Choose Ok and then Ok again


You are ready to go ^^


Off  course there some things that you need to check first, like :
1. Gave full rights for “C:\WINDOWS\Temp” folder depending on IIS user
2. Redistributable crystal version has installed
Reference : Sendy Santoso (http://geekydeveloper.blogspot.com/)