Rolf, this one worked for me: http://diffractionlimited.com/product/stt-8300/#shop-accessories Scroll down to SOFTWARE. Click on the one you need (Windows or OSX) under SBIGUDrv That same link should be under any of the "Accessories" sections for any of their cameras, but I think they're all the same DriveChecker.
That link is seriously mucked. Where did you get it from? It is supposed to be ftp://ftp.sbig.com/pub/SetupDriverChecker64.exe
I got it from your tread, the first one in this forum, but the http//: came from my computer when I copied the link . When I click on your link, I get the message "The website do not exist"
Your browser is apparently mucking it up by adding "http://" in front - just copy and paste it into the URL bar. There is only one DriverChecker64.