I have multiple clients with the same issue and Ive tried nearly all the tricks that I've read on this forum. What I think makes this problem a little different is that this only happens in the morning, when people come to work, never during the work day..... Overview: I have a Windows 7 Professional(64) based computers acting as P2P file servers on networks with 10 to 15 computers. When people come to work in the morning all of the XP(professional 32) based computers are occasionally denied access to the Win 7 file server. Rebooting the file server fixes the problem utill a given morning down the road. Error message: "computername is not accessible." You might not have permission to use this network resource. Contact the administrator of the server to find out if you have access permissions. The specified server cannot perform the requested operation". Windows 7 and Vista users never have the problem, they can always connect just fine, while none of the XPs can, whether they were left on all night or rebooted in the morning. There has never been a problem during the day, under a load, its always in the morning when people come to work. The systems acting as a file server do not perform automatic updates, updates are done manually. Windows firewall is the only firewall and there is no antivirus on the file servers. During the day the number of open files and connections are always within limits with connections timely terminated, etc, again this only happens in the morning when people come to work. A clue perhaps.... One network worked ok since March 2010 every computer other than the server was running XP pro. I replaced one XP computer with a Windows 7 system last week, now three mornings since then access was denied the XP machines while the new Windows 7 computer still had access rights. Again, rebooting the Windows 7 system acting as the file server corrected the issue. The Windows 7's share settings are pretty basic: Network Discovery on, File and print sharing on, Public folder sharing on, Media streaming off, 128 bit encryption, Password protected sharing off, Allow windows to manage homegroup on. I have not tried this yet: 1. HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management\LargeSystemCache and set it to 1 2. HKLM\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\Size and set it to 3 3. HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters\MaxNonpagedMemoryUsage and set to 0xFFFFFFFF Any help appreciated, Thanks in advance.

Three days in a row now, everything works all day then the same problem the next morning, reboot and all is well. No one has any idea? Any help is appreciated. Thanks

Hi, I notice when XP computers cannot access the Windows 7's file server, it will show error message "computername is not accessible". I suspend it is a network issue such as DNS not responding temporarily or others like this. You can turn off the Password Protecting in advance sharing settings to check the result. If the issue occurs again, please PING computer name or IP to check the network connection. Regards, NikiPlease remember to click "Mark as Answer" on the post that helps you, and to click "Unmark as Answer" if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.