MS Outlook Hangs Up

I am running XP Pro on my desktop and laptop and both started the same problem two days ago. When I try to access my email though MS Outlook (2007), a window pops up asking me to "Enter Network Password" The information is already showing in the windows for "Server", "User" and "Password". When I press the OK button, a new window pops up with the next account's information (I have three email accounts).

How can I get this back to normal so that my email opens as usual without having to verify account details each time?

 

Are all of the accounts on the same email server?
Did you install a windows update recently?
Does the email work after you confirm all of the saved info?
Are you having any other outlook issues? MS released a bad Outlook update last month.

 

All of the accounts are on the same email receiver.
A couple of Windows updates have been installed recently.
The email has not worked for about four days now but I can't be sure if this problem started exactly after the last update. I recently read that the update known as KB2412171 has caused problems with Outlook 2007 so I deleted it.
The reference is here: http://www.officeforlawyers.com/outlook/tips/2412171.html

 

The email hasn't worked? As in, even if you confirm the password, you still don't get your emails? After you confirm the password, will it ask you for it again?

My host made a change to our server and we had to change one of the authentication settings to get the accounts working again. That's my reason for all of the questions. I'm wondering if it's Outlook or if the host is causing the issue.