Hello, The black box in the screenshot you provided appears to be a notification or advertisement pop-up related to a media application potentially running on your system. It seems to be associated with "Kestine – allergialääke," which suggests it could be related to an audio or video stream playing. Here are some steps you can follow to stop these notifications from appearing: 
1. Identify the Source Application
 Check if there is any media player or streaming application that might be running in the background. 
- Task Manager:
- Press Ctrl + Shift + Escto open Task Manager.
- Look for any unusual, potentially unwanted applications running under the Processestab. For example, it could be media...