Configuration :: Schedule Task Doesn't Work With Web App Hosted In IIS

I am trying to use schedule task on the server from the web application hosted in IIS. I have written the code to create Task and passing the valid username/password under which this task needs to run on server. But I get an error: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED)) Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.UnauthorizedAccessException: Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))

ASP.NET is not authorized to access the requested resource. Consider granting access rights to the resource to the ASP.NET request identity. ASP.NET has a base process identity (typically {MACHINE}ASPNET on IIS 5 or Network Service on IIS 6) that is used if the application is not impersonating. If the application is impersonating via <identity impersonate="true"/>, the identity will be the anonymous user (typically IUSR_MACHINENAME) or the authenticated request user.

To grant ASP.NET access to a file, right-click the file in Explorer, choose "Properties" and select the Security tab. Click "Add" to add the appropriate user or group. Highlight the ASP.NET account, and check the boxes for the desired access. The same code works well with console and windows service and able to create task. I understand that this is security issue. My sample app is attached at: [URL]