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.