Why did my Xbox Live Account now use a Windows Live ID?

I have been hacked long time ago, and I phoned Microsoft all about it.I used a secondary Xbox Live Account and checked my primary Xbox Live Account,all my friends were removed and settings of it.Now I was able to retrieve my Xbox live Account.But all my preferences changed,like my friends were removed,also it says I have a Windows Live ID when I used my Yahoo E-Mail. So how do I change the email ociated to my Xbox Live Account? It only says that you can use a Windows Live ID but when I created my Xbox Live Account,I was able to use my Yahoo E-Mail.But it says Windows Live ID?Post some comments for parts you haven't understand so I will rephrase what I have said...