XML support not detected.?

I use a software program called PCLaw. It's a billing system. I've used it for years with no problem. Suddenly, today, when I try to start the program, it tells me,

"XML support not detected. Please install Microsoft's XML V3 or V4 support."

What is XML support? And how do I install it? For bonus points, any theory how I might suddenly have lost XML support (given that this program has worked for years now).

I am currrently using Microsoft XP.

Thank you for any help or assistance you may provide.

XML support not detected.?microsoft zune

One possible reason could be that PClaw has updated itself and now needs an updated version. XML is available from windows updates or from

http://www.microsoft.com/downloads/detai...

Download the msxml.msi file.