In addition to checking what Damir recommended, make sure the paths referenced by the IFILE lines in your TNSNames file are accessible from your Windows 10 machine. If they were defined as mapped drives in Windows 7, but not in Windows 10, that could also contribute to the problems you’re seeing.
As for the question regarding upgrading to a newer version with the same license, a good part of that would depend on whether you have an active maintenance agreement. I would contact your local rep to find out whether or not you have access to download the most recent commercial version. If you do, you may also need to get a new license key for your copy. There was an old style of license keys that was deprecated in Toad 12.5. So, if you happen to have one of those older-style keys, you’ll need to get a newer key from Quest’s licensing department. If you already have one of the newer-style keys, and have an active maintenance agreement, you should be able to upgrade using your existing key.
Feel free to let us know if you have any other questions.