Problems by installating Silver Fast 5

[Powertower]

Hallo,
I tried to install Silver Fast 5 when I start Photoshop/Import it say that there is no scanner, but if I start Nikon Scan 4 there is no problem working with it. I tried to reboot my computer but nothing happens.
Many thanks for your help

[RAG]

Powertower,

What about installing a fresh copy of SilverFast v6.4.3r9?