XP Pro email attachments

Hope I'm posting this thread in the correct section. I have a laptop with XP Pro installed using IE 6.0. My problem is receiving email attachments, not sending them. I have never encountered this problem when using Win98SE or Windows 2000. Nearly every attachment I receive, the file type is listed as unknown. At first I though it was Outlook Express. What I did to test this was go to mail2web and retrieve the attachment without going through Outlook Express. Same problem - file type unknown. At this point I could safely eliminate OE as being the problem. After a little more digging I came across a website that said the problem could be a MIME error associated with XP Pro. At his point I am totally lost.
Any help you can provide will be greatly appreciated. Thanks.

 

That's the problem - I don't know. When I go to open the attachment a dialog box appears saying, "File Type Unknown ". The file extension is .unk for the attachment.

 

This is about all I could find regarding this.

http://www.ronkaminska.org/unk.htm

Decoding Internet Attachments

Unable to read attachments sent by Microsoft Outlook / Exchange clients

 

I was able to change the file extension. After viewing the attachment in notepad the file extension was .wmv. I tried playing the attachment with media player 9 and it would not play. Error message invalid file format.

While still using notepad this line appeared, "This is a multi-part message in MIME format." Could this be an explorer issue? Thanks.

 

It appears this problem is coming from one sender. If this is the case I'm not going to worry about it. Thanks for all your help. This thread can now be closed.