Thanks for that, whoever you are!
(gulliver1/BayBoy1).
We're nearly there then. When you click on an attachment to open it, Windows needs to know which program to use. For example, if you click on a document, Windows will open it in Microsoft Word (or something similar). If you click on a music file, Windows will open it in Windows Media Player (or a similar program).
Your post suggests that Windows is trying to open the wrong program for the type of file in the attachment. You need to tell Windows which program it ought to be using (which is fairly easy to do).
However you've not answered Pinkyboyid's question about what type of file is actually in the attachment. We need to know the file extension. e.g. if the file is 'report.doc', it's the 'doc' bit we're interested in. Similarly, if the file is 'latesthits.mp3', it's 'mp3' that we need to get sorted out.
You tell us the file extension and we'll tell you how to re-associate the correct program with it.