A number of windows pop up when my desktop first appears with the above message. What is a white list, and how do I edit/purge it ?
The black and white list of your TeaTimer is the list where the blocked and allowed changes are listed.
Please right-click the TeaTimer icon in the system tray and select "Settings". There you will find 4 lists for remembered decisions (allowed/denied processes and registry changes). In order to remove an entry just click on the cross next to it. TeaTimer will then "forget" this decision and you will be asked again the next time.