The Microsoft Teams license activation is linked to The Open University issued student email address. You will need to activate your student's email if you have not already done so. 

Step 1: Log into student portal 

Step 2: Click on the link Office 365  (Alternatively, you can sign in at portal.office.com)

Step 3: Sign in

The credentials you'll need are:

• Email address oucu@ou.ac.uk - OUCU is your OU Computer Username that you were given when you first registered, e.g. jd1234. If you don't know your OUCU you can find it in your StudentHome profile page in Contact details. Double check the last part of the email address you're signing in with - it should end with ou.ac.uk. In the example, the student email address is jd1234@ou.ac.uk 
• Password - the password you use to sign in to The Open University.

Step 5: Chose the option to download Teams Desktop App (Note: the web app version have limited functionalities that does not support Remote Pair Programming)

Step 6: Sign in to use desktop app using the creditials from Step 3