Windows XP Machine not visible on Network

I just set up my home network (from scratch) so I could have all my devices in communication with each other. I have 2 PCs running Win 7 x64, an XBOX 360, and one PC with Win XP/SP3. I reset the router and recreated the network, and the win 7 machines can see each other perfectly, but I still cant get the XP machine to see the win 7 computers/have the win7 computers see the XP one. Also I can't get anything into connection with the XBOX.

Any suggestions?

Sorry if this question was posted previously...I don't use forums regularly.

I had a similar problem setting up my home network with a mix of OS and from memory in Win 7 you use Homegroups to see other Win 7 machines but that will not show any that are using XP - I think all I did was get the Win 7 ones to see each other then just mapped a network drive from them to the XP one then they all should appear. Apologies if this is not exactly how its done as its been a while since I did it but it may give you a start. I can't comment on the XBOX, as I don't have one, sorry.

I can't get the homegroups to work at all...the win 7 computers see each other through the Network, literally, the icon for network in the left hand paine in windows explorer shows both win 7 machines and they are completely accessible for each other.neither the xbox nor the win xp computers appear hear. i will try with mapping the network drive from the xp. thanks!