Register -SPWorkFlowService gives 500 not found internal server error.

I am trying to install and configure workflow manager since last many days but I am getting this 500.24 Internal server error or 500 not found error.

Workflow manager 1.0 refresh with cu2 installed perfectly but when trying to run the "Register-SPWorflowService" cmdlet to complete the installation, i get the following error : "An internal error occurred". I have attached the image.

The workflow backend service is started. Everything is fine except sharepoint 2013 is not able to find the workflow service.

And when i try to access the Workflow Management Site on port 12291, HTTP Error 500.24 - Internal Server Error An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.

Workflow manager is properly installed and I have done around 7 - 8 times new installation.

Sharepoint 2013 has SP1 installed on windows 2012 r2.

I am gone nuts. What could be the issue.

The log error says

Microsoft.Workflow.Client.InternalServerException: An internal error occured. For more details, please see the server logs. Client ActivityId : 349096cf-74bd-4f3f-a1df-6e9824fb80f9. ---> System.Net.WebException: The remote server returned an error: (500) Internal Server Error. at Microsoft.Workflow.Common.AsyncResult.End[TAsyncResult](IAsyncResult result) at Microsoft.Workflow.Client.HttpGetResponseAsyncResult`1.End(IAsyncResult result) at Microsoft.Workflow.Client.ClientHelpers.SendRequest[T](HttpWebRequest request, T content) --- End of inner exception stack trace --- at Microsoft.Workflow.Client.ClientHelpers.SendRequest[T](HttpWebRequest request, T content) at Microsoft.Workflow.Client.WorkflowManagementClient.SendRequest[T](HttpWebRequest request, T content) ... 349096cf-74bd-4f3f-a1df-6e9824fb80f9 12/15/2014 10:24:33.80* PowerShell.exe (0x2B88) 0x4574 SharePoint Foundation PowerShell 6tf2 High ... at Microsoft.Workflow.Client.ScopeManager.Get() at Microsoft.SharePoint.WorkflowServices.WorkflowServerPairingContext.RegisterFarm() at Microsoft.SharePoint.WorkflowServices.PowerShell.RegisterSPWorkflowService.InternalProcessRecord() at Microsoft.SharePoint.PowerShell.SPCmdlet.ProcessRecord() 349096cf-74bd-4f3f-a1df-6e9824fb80f9 12/15/2014 10:24:33.80 PowerShell.exe (0x2B88) 0x4574 SharePoint Foundation PowerShell 91ux High Error Category: InvalidData Target Object Microsoft.SharePoint.WorkflowServices.PowerShell.RegisterSPWorkflowService Details NULL RecommendedAction NULL 349096cf-74bd-4f3f-a1df-6e9824fb80f9

Kindly help me with this