I and my mother had one. I was running windows Vista, she was running windows XP, and lived in different areas with different internet providers, and different brands of phones. We both sent them back because they did not work correctly. Hers didn't work at all, and mine wouldn't receive calls, and when I called out it was very faint, you could not hear me talking. I went through all of their troubleshooting steps, and bought 3 different phones and it never did work. also, they claim they have customer service, and they dont. I tried to find a way to call them and never did. Gave up on them and got Vonage which does have a monthly fee, but we got it on a promotion and pay like $12 a month for the first year, then $24 a month after that. It works great, makes and receives calls, and has caller id, voicemail, call forwarding, and a bunch of other options are included, I just forget them at the moment. For me the magic jack was worthless, but we love vonage.