When in explorer, you select a jpeg, right click => open with, then beneath you'll find "select standard program" or "select default program" or something like that (my windows is a dutch version so I'm translating). Click that and you get recommended programs, but you also have a browse button, through which you can look for Xara. If you then tick "open this type of file always with this program", you should be ok. Similar procedures are to be used for any type of file you want to open with Xara (or with another program)