[R] Installation of XML library can't find libxml2.dll

[michael watson (IAH-C)]

Sorry to ask a (probably) dumb question, but I am trying to install XML
package on Windows XP, R 2.0.1, and I get the error: 

"This application has failed to start because libxml2.dll was not found.
Re-installing the application may fix this problem"

> library(XML)
Error in dyn.load(x, as.logical(local), as.logical(now)) : 
        unable to load shared library
"C:/PROGRA~1/R/rw2001/library/XML/libs/XML.dll":
  LoadLibrary failure:  The specified module could not be found.
Error in library(XML) : package/namespace load failed for 'XML'

Now, having read the website at http://www.omegahat.org/RSXML/, I find
that the package:

"uses libxml2, by default and only libxml(version 1) if libxml2 is not
present "

And here's my dumb question - what is libxml2 in a windows context and
where do I get it from?

Thanks
Mick