Including the following in a reply on this thread if someone is actually gonna be able to really help you.
OS (version and updates and SP your using)
System Specs.(desktop or laptop/notebook, CPU, RAM, video card(s), driver version, etc.).
Anything special in the way your running it (with models in a different directory, etc.).
That said, if you have not previously tried a clean reinstall, I would.
Note your account information (log on and password)
Backup your model (and model data) files into a temp location (outside the vghd folder to be safe).
Uninstall vgHD using the included uninstaller.
Reboot the system, then reinstall, start vgHD and activate it using you original account information.
Go to the "advanced settings" tab turn off the automatic updates, wait for the system to populate your model list.
Shutdown vgHD, load your models files back into the model and data files.
Restart and turn auto updates on, but with the models returned a, re-download will file check them.