You are talking different issues here.
First, if the phone will work in whatever country you are visiting in Europe will depend on what carrier/service provider you are using. Are you trying to use the one you use back home (where ever home is) or did you get a SIM from a company to use while traveling (to what ever country/countries traveling to)? The carrier/service provider is the one that can tell you if the phone will work for them and in the location(s) you will be in. No one else can. Different carriers/service providers use different networks and have different requirements, so while a phone may work for one, it won't work for another. Contact the company (carrier/service provider) you plan to use where you are going and they...