I lost hours trying to resolve this:
“ORA-12154: TNS:could not resolve the connect identifier specified”
It requires lots of determination not to swear and rant about the possible causes of this message but in my case (Windows 7 64bits), it turns out that Toad doesn’t like to be installed in a folder with ‘()’s like ‘C:\Program Files (x86)’
I installed in C:\Toad\ and the problem is resolved.
Of course to reach there I had to resolve some other issues (for the same error message) like:
– Installing 32bits version of Oracle Client (10.2.0.1)
– Instant client didn’t work for me.
Hope it helps.