Hi George,
the problem isn’t the drive you installed Cubase on, but a file that got corrupted when updating from 7.0.2 to 7.0.3 or from 7.0.3 to 7.0.4. It is a known issue that is best solved by re-installing Cubase 7.0.0 and then skiping those 3 updates and going straight to 7.0.6. You don’t have to re-install everything, no content, no plugins… just the Cubase Core application.
Hope this helps
Regards