Unable to get the Open property of the Workbooks class

Hi Experts,

I am trying to work with Excel files from my classic ASP web application. It was working few days ago but today it stopped working suddenly. Perhaps it is due to some automatic windows updates. Here is a snippet of code that gives error:

dim objApp
dim objBook

set objApp = Server.CreateObject("Excel.Application")
set objBook = objApp.Workbooks.Open(server.MapPath("MyExcel.xls"))

While executing this code, it gives the following error:

Microsoft Office Excel error '800a03ec'
Unable to get the Open property of the Workbooks class

The same code works on my desktop and earlier it was working on the server also.
The server configuration is - Windows Server 2008 R2 x64, Microsoft Office 2007, IIS 7.5

Thanks in advance for all your efforts to sort out this issue.