Coming here for some help because you guys have fixed all my problems in th epast. today, my problem is that my homegroup can't working since router change. I have a PC and two laptops running Windows 8 HP which have been happily connected via a Homegroup since Windows 8 Beta.
Last week I had to replace my router and at the same time changed the wireless SSID and security key which the two laptops use - the PC is connected via ethernet.

To my surprise, both the laptop can see each other, but the PC can only see one of the laptops . anyone can give some suggestions?

You may need to create a new Homegroup because of the router change.

As for the machines that can't see each other, which A/V software or third party firewall are you using?

can you tell us know,what the spec of your 2 PC and laptop.

give a more details, can easy to solve it.