That would be a PC question. Most likely it's some configuration buried in windows and tied to the iCloud connector app that allows you to direct the default for friends and business address & phone information. Windows controls this generally per program as to how a given program will handle a file type passed to it. I haven't dug into win 7, or 8 in over a couple years so I would check iCoud preferences first and then internet prefs based on file extension to see if there is a pointer or some standardization in system settings.