Library not defined error

Hello everyone !!

I am facing a very weird problem which I cannot seem to solve. I have a Project file with macro running. It was perfectly fine until last week. I fired up project today morning and I am getting the following error :

Run Time error '-2147319779 (8002801d)':

Automation Error

Library not registered.

Option Compare Text
Option Explicit

Dim Pjt As Project
Dim ToBeOutdent, line As Integer

Sub GenererGantt()
Dim tsk, tsk2 As Task
Dim TskID(10), Test_Number2, Test_Duration, Test_Qty As Integer
Dim Defect_rate As Double
Dim PN, PrevTask, Test_Name, Test_PartNumber, Test_MakeBuy, Test_Phantom, Test_Supplier, Test_Inspection, Test_StdCost As String
Dim XL As Excel.Application


    Application.AppMaximize

    'Input name of Excel file where data are stored (from folder "D:\Documents\My Delivery Maps\")
    PN = InputBox("Enter Excel file name")
    If PN = "" Then Exit Sub

    'Project creation
    Application.FileNew False, , False
    Set Pjt = Application.ActiveProject
    Pjt.ScheduleFromStart = False

 The bold-italic area is where it is showing the error. (New Excel.Application)

Steps after the error : 

1. I have repaired my Office 2010. I currently use the Project 2013 version.

2.  I unregistered and reregistered  MSCOMCTL.OCX file.

3. I have checked the reference for Excel in the reference section. 

The problem is still persisting. Any help on this would be HUGE !!

Thanks,

Abhi