Hi exo -
I'm sorry, but I may not have explained the situation well enough: You
cannot currently install the driver software to any drive other than the one holding Windows and LabVIEW.
It can't be done, and if you somehow manage to force the installer to do so, the software will not work correctly. We may decide to change this in a future release, but all existing versions of NI-FGEN are subject to this limitation. I'm afraid you'll have to repartition the drive to allocate more space to C:.
On a side note, IVI is defined
here, and a link to the IVI Foundation site is provided on that page.
David Staab, CLA
Staff Systems Engineer
National Instruments