Hello, sorry for this stupid description in the title but it describes best what my problem is: We have a little networks with a Windows Server 2008 R2 Domain controller server and several Windows 7 Pro workstations. All updates installed. HP Proliant Server, enough Ram+CPU, up-to-date drivers. HP and Dell desktops, also up to date with drivers. Usually everything works fine and reasonably fast but sometimes - more often for some, rarely for others - it happens that the access to folders on the server becomes very, very slow. Like minutes to open a 1 or 2 MB pdf file. What I recently found it is that whenever I experience these delays and I try to access the server through Windows Explorer by \\Server I get the following Error: "Open Folder \\Server is not accessible. You might not have permission to use this network resource. Contact the administrator of this server to find out if you have access permisstions. The remote procedure call failed and did not execute." Seconds before I still had access permissions, so this is not the problem. Also accessing through \\Server\Share works ok. I can browse the server structure in normal speed but when I click a file it slows down terribly. Strange is also that access to \\192.168.100.10 is working fine, as is \\192.168.100.10\Share. Also ususally after a few minutes it is fine again. In most cases it is also cured when I pull the LAN cable on my workstation and plug it back in. What I also discoverd is: for me it happens quite regularly when I edit a Visual Studio ASP.net project which is stored on the server and I try to debug it. When the VS development webserver runs it may slow down alost to a halt and speed up instantly when I stop the webserver. (The webserver is installed and running on my workstation but accessing the files stored on the server!) Annoying enought, but it happens only about one out of 15 times. So there is not consistancy. NSlookup and ping are both ok before, during and after the problem exists. Ping by name, fqdn and ip address. Other users in the network are not affected at the same time, they may have a problem at a different time, but can access everything at full speed while I'm struggeling. Also I can access our database server through Windows Explorer at normal speed while the data server causes trouble. It seems that two factors may be involved: 1) The network load between the server - many small files are much more 'dangerous' than a some huge files. 2) Access of the server by name causes problems, by ip-address is ok. Even if it seems not a DNS issue as nslookup is fine? I'm happy for ANY suggestions because this is driving my crazy!! And worst of all, I have no idea what or where to search and cant even ask my friend Google for help because the error is so unspecific. Thanks in advance, Markus

Hi Mark, Please keep your every network adapter is up-to-date. Beyond that, you discovered access of server by name causes problem, by IP address is OK. So I recommend you try to refresh DNS: Type CMD into search input box of start button; Right click and choose Run as administrator; Type commands ipconfig /flushdns, Enter. Best regards, Karen Hu