I’ve done all your suggests, but the problem remains.
But I’ve found the reason of the problem.
If I run Toad as a domain user with “Administration” privileges on local machines I’ve the problem.
If I run Toad as local Administrator user of my PC, I connect to Oracle successfully.
So it’s only a problem of privileges!
It’s strange: my domain login ENTERPRISE\valeriose has admin privileges on my pc but with this user Toad fails with error “Can’t initialize…”
I’ve also attempted “Rus as Administrator” by contextual menu but without success.
If I use my local user “MYPC\valeriose” that is local administrator Toad connect to Oracle!
Any suggest to use Toad with my domain login?