XPS is a way to gain greater control over how a document looks both on screen and on the printed page. As XPS is different to standard printing, you may need a special driver to use XPS files on your printer.
XPS stands for XML Paper Specification. It was developed by Microsoft from an open source set of guidelines. An XPS file contains not only the content of a particular document, but also specific instructions about how it appears on screen and how it should be turned into a printed document. The idea is to make sure pages look the same when printed out as they do on screen. As a concept, XPS is similar to Adobe's PDF format.
Many printers will be unable to use XPS files to print a document without the addition of an extra driver, a software tool that acts a bit like a translator between an operating system (such as Windows) and a hardware device. If you have trouble with XPS files, check your printer manufacturer's website to see if an XPS driver is available for your model. Check these installation instructions carefully, as they may differ from those for ordinary drivers. For example, with some Canon models you must first uninstall the standard Windows driver for the printer before installing the XPS driver.