Posted 20 September 2009 - 07:54 PM
Computers 2 and 3 are asking for username and password of Computer 1.
But Computer 1 is Windows 7. If it were XP, wide open XP, it wouldn't ask, because, at least on the Home version it's all under the GUEST account.
But Windows7, I suspect, works differently. If it has good security as people claim it does, you may need to, in Windows7, somehow permit the users of Computers 2 and 3, as well as, of course, having setup few folders where you permit other computers to work them. Pinging included.
I now see that you have issues with XP as well. Follow caperdog's suggestion to try without the firewalls, same workgroups, some folders to permit sharing, reboot if needed, as this sometimes may help.
Do all these computers have different IP addresses? The more I reread the questions, the more it looks like some basic setup is not yet finished. For instance, are all these wired connections? If not, is the router setup properly to permit all the MAC addresses in the security section?