In Microsoft Edge, go to https://www.harrisservices.co.uk:

And click on "Remote Support".
The following window is then displayed:

Enter the session code provided by the Harris Support Staff and click "Continue".
The following window is then shown:
Click on "For Windows"
A small file is downloaded and will show in the list of downloaded files:

Now click on "Open File" and the session will start. Windows will then ask for permission to allow TeamViewer tomake changes on your system:

Click on "Yes"

and the following confirmation will be shown. To continue and allow access click on "Allow Access"