Hi Bertie11, Welcome to SF,
It sound to might that the issue is going on with the Context Menu. You might wanna try ShellExView
The rule is to disable non-Microsoft context menu handlers one-by-one and verify if the problem is solved. If disabling one does not solve the problem, undo the disabled item and disable the next non-Microsoft handler. Do the same until the problem is solved and finally identify the culprit. Scroll right to see the Company Name
column in ShellExView.
Hope this helps