I'm been working with Wix for a few weeks now, and a really like what I see with the technology, however it can be painful trying to do some obvious things due to limited documentation and examples.
Today I wanted to create a user at install time, a simple problem with a simple solution:
CanNotChangePassword="yes"
CreateUser="yes"
FailIfExists="no"
PasswordNeverExpires="yes"
PasswordExpired="no"
RemoveOnUninstall="yes"
UpdateIfExists="no"
Disabled="no"
Name="New Service"
Password="pa55w0rd">
<GroupRef Id="GroupID"/>
</User>
Straight forward enough however I was getting the following error:
The Component element contains an unhandled extension element 'User'. Please ensure that the extension for elements in the 'http://schemas.microsoft.com/wix/UtilExtension' namespace has been provided.
Although this is a trivial error to fix it took a while for the solution to dawn on me, after not finding much help on the internet. The problem is that the UtilExtension is responsible for creating users and there is no reference to the DLL.
To resolve the problem I simply needed to add a reference to WixUtilExtension.dll and the problem was solved.