Outlook 2007: Network Password Issue

I've seen similiar issues in previous threads, but I'm not sure how I should fix my problem. I am trying to set up Outlook 2007 for the first time. After entering my basic info (name, email address, and password) and clicking next I'm asked to enter my user name and network password. The thing is, I don't have a network password set up yet. The thing is, the password field was already filled in, but clicking next only got me a 'try again' window. I attempted a handful of passwords, but to no success. Am I missing a step here? Did I forget to set something else up? I am trying to connect to a couple of email accounts, the main one being my yahoo account. Any help would be appreciated.

Oh, and btw, I tried looking in the "Protect" folder (C:\Documents and Settings\user\Application Data\Microsoft\Protect) where I guess the password is stored (not really sure, just looked it up on the internet) and the folder inside (with the long name) was empty. A password recovery program specifically designed for Microsoft Office that I temporarily downloaded said that I had no Outlook account on my computer.