Solved! Go to Solution.
This was bothering me for hours today, but I finally solved it because of your post!
I was getting the error "TNS:listener was not given the SERVICE_NAME in CONNECT_DATA No extended error" because Oracle wasn't being pointed at the proper tnsnames.ora file.
What fixed this for me was step 3 of your answer:
3) creating a system variable TNS_ADMIN that points to the folder containing the tnsnames.ora file.
From the Environmental Variables window, click New under the System variables section.
Variable Name = TNS_ADMIN
Variable value = The directory location of your tnsnames.ora file
Thanks for posting this!