outlook password invaild on my cell?

I have a Samsung Galaxy3 and had to do a wipe and restart and reinstall all apps. I am trying to add my Hotmail acct to my cell and I enter the correct username/email and password (it works on my PC) but when I enter that info on my cell App it comes back with user name and password incorrect and/or cant be authenticated from server. Why is this happening and how do I fix it. I didn't have this issue before I had to wipe my phone.