Hi all.

Having trouble setting up some replacement PCs in the office. I've installed Outlook 2010, and usually it's extremely easy to set up. Just email address, 365 password, and it's done. 
This time, however, I keep getting prompted for a password, and the login address keeps changing to MichaelJ@subdomain.domain.com, instead of Michael@domain.com.

Attempts to configure manually have failed, usually if this happens I change the original email address field to michael@domain.onmicrosoft.com and then, when the password box pops up, change the address to michael@domain.com.

I saw a fix online that involved setting the security settings to Anonymous authentication, but I don't have the option available.
I've tried restoring the PC and starting again.

This problem has happened on three new PCs, all setup from the same install disc, and all using the product key of the Office suite of the PC the new one has succeeded.

Any help you can offer is greatly appreciated! 

Thank you,

Levi