I accidently allowed some kind of add-on or something with the Spybot Tea Timer. It asked as some pop-up add came up, which isn't good. How do I reverse that?

First you'll have to set windows to show hidden files:
How to see hidden files in Windows

Right click on the TeaTimer icon, in the Task Bar, and select Exit.
Then navigate to:
C: \ Documents and Settings \ All Users \ Application Data \ Spybot - Search & Destroy \ Snapshots
Delete all of the .reg files (only the .reg files) in the Snapshots folder.

Then reboot, to restart TeaTimer.
It should now be, reset.