Windows 7 no longer access from XP 64 on computers with 7

[angel8888]

When a network connecting two Windows 7 64-bit among themselves, can no longer access from XP 64 on these computers.

If I do not go with Windows 7 at the second similar Windows 7, the network and access between XP and 7 is wonderful. As soon as there is a connection between two windows 7 based computers - XP does not have the right to access to them. But windows 7 computers at the same time have access to computers with windows xp

Only helps break the link between windows 7 based computers and reboot ...

 

[Trouble]

I'm not sure that I understand the problem you are trying to describe. What exactly is the "link" that you break before rebooting and then being able to access the Windows 7 machines again from the XP machines.
Is it possible that you are talking about using the Windows 7 Homegroups feature. If so this is not supported by downlevel clients like XP and you will need to use Workgroup and simple file sharing to support cross platform networking.
When you say "can no longer access" what exactly happens? Can you still ping the windows 7 machines from the xp machine by ip address and netbios name?
Can you access a share using the ip address of the Windows 7 machine from the XP machine, something like
Link Removed?