Recently I again had a problem accessing a folder shared by a Windows 7 machine from Windows XP, causing "
System error 58 has occurred." on the client and event #2017, "
The server was unable to allocate from the system nonpaged pool because the server reached the configured limit for nonpaged pool allocations." on the server.
I found the frequent advice to set
HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\Size to 3, but since I had the luxury of not having any other connected clients, I just restarted the LanmanServer which is provided by the imaginatively-named "Server" service.