Do not attempt any fixes via the registry. Doing so may not end well.
That said, I am not sure about the question being posted.
When you right click the recycle bin icon there should be menu choice for "Empty Recycle Bin".
However, some AV software does add a "scan option" to such drop down menus as a convenience. Other 3rd party utilities may likewise add menu choice as applicable to the app's purposes.
So, just to be sure: Spybot added a drop down menu choice that has remained after Spybot is/was supposedly uninstalled - correct?
Is the recycle bin the only folder where the Spybot scan option is still appearing?
When you uninstalled spybot did you use the uninstall process via Windows, Spybot, or did you just delete the...