I was trying to run the default website in a default installation of IIS on Vista, and I got this error message:

What the ...? Who comes up with crap like this? Unbelievable... even the error code is useless to search for, as apparently there are hundreds of other error conditions in Windows that bring up the same error result. Does Windows have so many error conditions that the value range of a 4 byte uint is no longer large enough?

So what was the problem? Very simple: another application was already listening on ports 80 and 443 (Skype - does that by default, thank you very much). Apparently it's really hard to have an error message like "Another application (Skype, PID: XXX) is already listening on port 80.", or at least "Error trying to listen on port 80." Well, it's only IIS 7 - maybe they'll get it right for version 22 or so.

Just came across this, and I thought I'd document it for myself and others. I was trying to install SnagIt on a newly installed Vista system and every time the installation just stopped right after the first wizard page, giving me a "Fatal Error Message" with the detail information "Installation ended prematurely because of an error." I had already installed Camtasia before SnagIt, so I thought this was rather weird - seemed like if the installer worked for one of the products, it should work for the other just as well.

I searched the TechSmith forums and quickly found a link to a page where they already describe a solution to the problem. Now, the funny thing is that I already knew about that problem, having encountered in recently when installing the BlackBerry desktop on Vista, and I had already applied the solution on that machine.

Well, I did the "regsvr32 ..." step once more, and it seemed to work - I was able to run the wizard and get past the point where it had previously stopped working. A few pages later is where the license key is requested, and I had to tab over to another app to find where I had stored the email with the key, and open it in an editor. I copied the license key, pasted it back in the SnagIt installation wizard, clicked Next, and .... I got the same Fatal Error message once more. Looks like somehow the VBScript runtime got unregistered on my system while I was looking for the license key.

I registered VBScript yet another time and ran the wizard. I still had the license key in the clipboard and I was careful to step through all the pages without doing anything else. As a result, everything went just like it should, and I got SnagIt installed. I don't currently have any idea what caused the problem... I'm using more or less the same set of applications that I already had running on an old Vista installation, and on that system I had never had any problems with the SnagIt installer.

In any case that VBScript thing seems to be a running gag in Vista... I really wonder why it's not registered by default, this seems to cause quite a few problems.

Update: I just found that Corel Draw 12 has the exact same problem, and once more VBScript had been uninstalled on my machine... guess I should figure out why the uninstalling happens all the time.