Bit of a novice here but to setup pear you run the go-pear.bat - i think that the right name - and then you run a reg file that is created which sets up some system wide paths i think you can then from the windows command line run --> 
 	
	| pear.bat INSTALL <package name> | 	
 etc..... which all worked fine with xampp.
I am now on  a clean OS install and haven't installed xampp yet but i thought i might and was wondering about using pear with both phped and xampp can it work with both seperately.
It would be like having 2 seperate pear packages installed, i would imagine there would be conflicts with default paths and such as you have to register environmental variables in windows i think... which would mean that you couldn't have a default path for both xampp and phped, well in my thinking anyway.