How do I remove the extra TNS entries that I don't need from the Connection Manager drop down list?
RESOLUTION 1:
1. Open the TNSNames Editor at the bottom right of the Connection Manager window
2. Highlight any entries you want to delete and press the Red X icon
RESOLUTION 2:
1. Close out of Toad and go directly to your TNSNAMES.ora file
2. Open it with Notepad and delete the entries that you don't want
3. Open Toad again and you shouldn't see those entries anymore
Note: You should always backup your TNSNAMES.ora before editing it.