The Microsoft XPS printer recently appeared on my system, not SURE why. However when I prodice an .xps document and try to open it , Mozella Firefox opens and seems not to know what to do with it.
I have tried to download xps READER but I keep getting told that Microsoft .net 3.0 already exists as a newer version.
I am using Windows XP Service pack 3.
Any suggestions?Essentially, XPS files are Microsoft's own document format, that they hope will rival Adobe's PDF format. I think XPS viewer assumes that the default browser is Internet Explorer, but it sounds like you have made Firefox your default. You could try this: In Firefox, install the IETab extension then configure it to open XPS files from Tools->IETab options. They then open in an IE tab WITHIN Firefox without having to switch browser. But honestly, if you are just noodling around with XPS files, personally, I would just forget about them unless you have some special reason that means you have to work with them.

https://addons.mozilla.org/en-US/firefox/addon/92382/

Or just right click any XPS file and CHOOSE "Open with..." then select XPS Viewer if it is visible or browse for Internet Explorer then check "Always open this TYPE of file with this program" then click OK

If you want to fool around with XPS documents, you may want to download the Microsoft set of sample XPS documents from here (Winzip self-extractor, contains 354 files!)

http://www.microsoft.com/whdc/device/print/xps/xpssampdocdwn.mspx