Errors and incorrect display

[Peggy]

1. When I start outlook, I receive an error message
advising ZFEXT.DLL could not be found? It goes on to
advise the Detect & Repair may fix the problem. It does
not.

2. I send lots of email with urls. Suddenly my emails
are going out looking fine but are delivered in plain
text with the url information duplicated. They go with
an attachment "ATT xxxxx.txt" What's changed?

3. I have extra lines in email. When I return, it does
a double space - how to change?

Thanks for the help!