Recent time I reinstalled OS.
After running TDM.exe first time, splash appeared for a moment and error message after that. Message was: unable to write/create (whatever ) subdirectory … (some paths pointed to user profile, I believe: …AppData\Roaming\Quest Software\Toad Data Modeler)
After running the exe again, TDM has been started successfully.
I know it is some minor issue and TDM is intended to run after correct installation process. But maybe description of this behaviour will help in some way.