FJ Software

When launching MPE, Windows XP (i.e. inbound-only firewall) immediately prompts whether to block/unblock it (i.e. from creating a server by opening inbound ports). Why is it needed? Especially since I don't notice anything wrong when choosing to block it.

The inbound port is used to find out the WiFi IP of your phone. If you block the inbound port then you have to enter the IP-Address of your phone in the settings manually, besides this MPE will not connect automatically to your phone if it comes in WiFi range.

The inbound port is in general only used for the WiFi connection

But it finds that IP even when I choose "block" in the firewall's block. How do you explain that?

MyPhoneExplorer does cache the last WiFi-IP of the phone. If you did allow the connection the first time then it will work even with blocked firewall as long the phone has the same WiFi IP.