I have 2 outlook accounts, I want to be able to see both at same time

I have recently opened a new outlook account for a small business I've started, which means I now have 2, I'm fed up signing in and out all day to check both inbox mail. I want to have one in each tab of my computer, is this possible? Also when I used to sign out of my account before, to sign into the other, I would just get the sign in page, now I keep getting redirected to MSN page and when I try and sign in again it opens a new tab! It's driving me crazy, this has just started happening in the past few days, can anyone help? Oh and please put your answer like your talking to a child as I'm so computer illiterate! Thank you