Cannot view e-mail message

OK here is the scoop. I receive e-mail and can tell I got e-mail. I can reply to that e-mail. I can forward that e-mail to another computer and read it. BUT I cannot read it on my machine. I can also save attachment to my harddrove and then read it.

I have Windows XP Home and Outlook Express.

I had this problem before but I always needed to select START, RUN and type a command and run it and my e-mails would show. I lost that command. Now I have to save all my e-mail as attachments.

This started happening to my computer out of the blue about 2 months ago. Microsoft would not help me.

Any ideas?? Thanks