I have a Windows 7 machine on a Server 2003 domain. Currently it is the only one on the network being used on a daily basis. Occasionally after an hour or two (unknown exactly how long) files on a network share become unavailable, showing a grey x over them. When clicking on the grey X file a message comes up saying the file cannot be found. This only happens to some files not all, and I cannot obtain any pattern. The files are there just not to this computer. Also these are files in the same folder, in other words some files in folder X are available while some files in folder X are not. Rebooting the computer solves this issue, for a short time. My first guess is a network issue, but since it happens to only some files on a network drive and not all I am a bit lost as to how that happens. The rest of the machines are XP and have no difficulty. I will add that the connection this computer is attached to is very slow, so i wonder if there is something new in windows 7 that is more "sensitve" to slower connections.

Where are the shared folders located? Are they on a Network device such as NAS? If the folders are on a computer, I suggest you temporary disable the firewall on the file server and check the result because such issues can be caused by firewall. If the issue persists, please follow the steps below to change the default NTLM authentication level. 1. Launch gedit.msc from Start Search box. 2. Locate to: Computer Configuration\Windows Settings\Security Settings\Local Policies\Security Options\Network security: LAN Manager authentication level 3. Change the policy setting to “Send LM & NTLM - use NTLMv2 session security if negotiated”.Please 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.

No the files are on a file server which is also the DC. Firewall is off on this server already. I will try the other setting change next week. Thanks for the response.