Ralf,
I'm sorry to hear about the problems that you are having with the Update Wizard. My only suggestion would be to review your Internet Options, and try adjusting some of the settings related to proxy, http, and ftp. I personally have tried adjusting a number of my Internet Options, and I have not been able to reproduce the error that you are seeing. You might also want to talk to your Network Administrator and see if they are able to help.
Regardless of the outcome of that, I would like to assure you that it is easy to find the most recent versions of your National Instruments'(NI) software. In general, NI does not release frequent patches for software, so checking on a daily or weekly basis is probably not a necessity (For example, the last version of
LabVIEW, LabVIEW 6.1, never needed an update). In order to check if you have the most recent versions of LabVIEW, open MAX and expand the Software heading. This will allow you to see the installed versions of all your software. Then you can navigate to the following website, which lists the most recent versions of all of NI's software:
http://digital.ni.com/softlib.nsf/webcategories/9AD71162B755F0E786256BBC005F001A?OpenDocument&node=132060_US
I am hoping that this will help you get going in the right direction.
Jed R.
Applications Engineer
National Instruments