I am having the same problem.
In the previous reply, it was mentioned the following:
From what I understand, Winzip is publishing announcements a new WinZip version is available, KTS, recognises the "announcement", offers (to you) to update WinZip, however, when the Winzip update is "managed" via KTS, the Winzip software that's "pushed" onto you machine, is Winzip "TRIAL" version, have I got that correct?
I believe your understanding is correct.
The update to WinZip version 24 is not a free update. Thus, the reason why the newly installed version is a "trial version". Since it not a free updated, the "Version 23" license numbers does not work.
WinZip states that they are not pushing the update out. (Please see below)
If you are finding a newer version of WinZip installed and you did not install it, I do not know for certain how it got there. The only feature in WinZip having to do with new versions is the Check for Updates feature. All that does is to check records on the update server against what it finds in your registry to see if you have the latest version installed or not. If you don't, it lets you know that something new is available. It does no downloading and it does no installing.
For WinZip to be installed without your knowing, there would either have to be a group policy install in place or there would have to be another application installed that performs automatic upgrading of programs silently. I have heard from a few customers and have found that Vipre/AVG TuneUP/Kaspersky Internet Security will automatically update third party applications, including WinZip.
not sure if the above information will help.