Hello Simon, sorry about your problems. My name is Marco and I will do my best to help you.
For the CTRL key, check in your browser shortcuts.
Right-click on your browser shortcut (which is located in the desktop for example).
Select "Properties".
Open the "shortcut" tab and look in "Shortcut key" case if CTRL key is entered. IF yes, replace it with None
Click Apply and OK
And for the Windows key, you can go to the Device Manager to delete the keyboard drivers and reinstall them.
To do this, right-click on the Windows start button and select Device Manager.
Next, find the keyboard, right-click on the driver and select Uninstall.
Restart Windows to reinstall the default keyboard drivers.