Your only choice is to upgrade Hoster. Your version 3.120 does not work with Vista. Click this to order it for $39.99:
http://www.mtu.com/catalog/shopping_...el=Hoster33UpG
For the record, MTU does NOT recommend using Vista at this time. There are too many problems that Microsoft hasn't fixed yet. If you do choose to go with Vista, please read our FAQs related to it so you can avoid some of the already known and identified work-arounds.