"Can't contact LDAP Directory server (81)"

[Brookston]

I've gotten the following error message whenever I click the "To" icon when beginning an Outlook email:

"Can't contact LDAP Directory server (81)"

What does this mean??

I formerly used Microsoft Outlook Express. I switched to Outlook months ago and have been "limping along" with this malfunction ever since. After encountering the error message, I must go up to a drop-down menu and manually select "Contacts" rather than "Address Book" and find one of an old collection of email addresses there (over time, I've come to realize that there have been no more additions to this contact list since I migrated over to Outlook). Perhaps I only THOUGHT I successfully imported my address book from Outlook Express way back when (although I remember having gotten some sort of "success" window at the time). So how can I get this fixed so that 1) a fully functional address book comes up when I click on the "To" icon, and 2) new email addresses can be manually or automatically added to this Truly Functional Outlook address book?

Can you help?

[FAT64]

Is this Office XP by any chance? If so, you need to install Service Pack 3.

[Brookston]

"Aha!" he exclaimed hopefully.

Thank you!

Yes, it's XP and I didn't know there WAS a Service Pack 3. I will look into that immediately and bring back a good report soon. In the meantime (no to demean this promising and logical-sounding solution), the "welcome mat" is still out to all other potential solutions.

Brookston clear.