Clicking on a hyperlink in an email in Eudora gets you an about:blank Internet Explorer Window like this:
This is happening all of a sudden because you recently downloaded Microsoft Windows Internet Explorer 7.0 for XP!!!!!
The Cure is to:
#1 uninstall MSIE 7 and
#2 stop the MSIE 7 install featuring on the Microsoft Windows Update Options and the darned thing installing again!
That's the lot!
Enough? [contact me if this helped you ]