Why can't I connect to shared folders on the local network after the first connection?

Question

Network administration

Set up a local network between computers running Windows XP and Windows 7 via a twisted pair cable. He sees everything, everything works BUT! The first time I go to the shared folder - everything is fine. Some time after using the shared folder ( but not during ), an error appears when you log in again.
"No access to the PC. You may not have rights to use this network resource. Could not connect to the network due to matching names"
The names are different. This only happens when connecting from Windows XP to Windows 7. In the other direction, everything works fine, all the time. After a while, the error does not appear and again you can climb the shared folder.
Please tell me how to remove this error?

Answer 1

Local Policies - in security settings find:
"Do not allow enumeration of SAM accounts and shares by anonymous users"
And disable it.