At the bottom right corner of the screen, click the Connection Manager icon again, select the WLAN "eduroam" and click Connect. If a connection attempt has already been made, first click on "Disconnect" and then on "Connect" to make the changes effective.
Now the dialog for entering the access data appears. Enter the user name of the university account followed by "@uni-bremen.de" and the WiFi-Password. After a click on "OK" the connection should be established after a few seconds.
On some computers we have observed that user name and password have to be entered several times before the connection is established. Unfortunately, we have no influence on this peculiarity of Windows. If necessary, please enter your access data several times before you suspect another problem.