Missing Office.Interop DLL

Can somebody help me out here. I have difficulty locating the MS.Office.Interop.Word and .Excel DLL's in the .Net / COM Components. I successfully located and referenced the Interop.Excel component in the past few months but suddenly they are missing. What has happened or have I done wrong? If I need to reinstall, how? Thanx a lot.

This is what it should look like if you are trying to reference Excel (the version may vary):
Attachment 86830
Do you see this in the component list?

Yes, I do. But I am looking for the .Office.Interop. NOT the. .Office.Core, which I you are referring to. Please explain if I am missing something.

I got it. Thanx