Want to move Windows live mail adresses to Outlook.com, but use aliases in Windows Live and now Outlook does not recognise these addresses when trying to move then accross

Hi

The title pretty much sums it up. I want the functionality of Outlook.com so I want to bring two Windows Live addresses across. These are business addresses from a website domain, so I created them on Windows Live using the POP and SMTP information provided. Now that I have opened a Outlook.com account and want to move these emails across, I get the error message that Outlook does not recognise these a0ddresses as from another Mocrosoft account. I want to bring my inbox and sent items history across to Outlook.com and pretty much start using Outlook.com to run these addresses. I don't know if I have an alternative Windows Live email address that I should be using for this setup or if so where to find this address and password

I have created just aliases using these two email addresses on Outlook.com, if this is sufficient, how do I move all my inbox and sent item archives across? 

Help! Please

Charlotte