Two computers should not share a Modem if you want to Network them.
Check you Modem it might be that it is a modem/Router combo.
If it is Not a Modem/Router, buy a Cable/DSL Router, connect it to the Modem
and plug the two computers to the LAN side of the Router.
Once the hardware is done configure the computer sharing system.
Successful Sharing involves some general consideration in Network settings, http://www.ezlan.net/sharing.html
As well as specific adjustment of each computer according to what it is
allowed to be shared.
Vista File and Printer Sharing- http://technet.microsoft.com/en-us/l.../bb727037.aspx
Windows XP File Sharing - http://support.microsoft.com/default...b;en-us;304040
Printer Sharing XP - http://www.microsoft.com/windowsxp/u...utt_july2.mspx
Windows Native Firewall setting for Sharing XP - http://support.microsoft.com/kb/875357
Windows XP patch for Sharing with Vista - http://support.microsoft.com/kb/922120
"Robert Judge" <RobertJudge@xxxxxx> wrote in message
>I have a new desktop running VISTA and an old desktop running XP. They
> a modem to connect to the internet.
> I used the "Easy Transfer" process to copy the XP files to the VISTA PC.
> have found some shareware that claims to allow me to be able to continue
> synchronize the files between the computers. I would like to connect
> two computers, in order to do so.
> How do I connect the computers?