Hello
You mention it failed on some versions of XP. Did they previously have the cwui control installed on it? You can try uninstalling your software, and then making sure that you dont have the cwui control installed on the machine anymore. Look for a control called cwui.ocx file. If you find it, unregister it by using regsvr32 /u on it. Delete it after it has been unregistered, and then reboot. Then try installing your software again, make you have admin priviledges.
Check out this
link for registering activex controls
I hope this helps.
Bilal Durrani
NI
Bilal Durrani
NI