I have 2 Windows 7 machines (both quad core, 8GB RAM). Both map drive letters to the same NAS box. One one machine the network connection is instantaneous and directory listing of files in fast. In the other machine, the map network drive says "Attempting to connect to...", which takes 20 seconds and then another 10 seconds to open the window with the directory list. Changing to another directory takes a few seconds. Sometimes if I try to "CD dirname" it says it can't change to that directory (which exists) In safe mode with networking it's fine. When doing a clean boot with no startup programs and only the Microsoft services, it is a problem. It's not auto tuning or RDC as I've tried changing those to no effect. I just ran wireshark and see that it's doing HTTP requests to port 80 on the NAS box from the slow machine rather than tcp requests to port 445 which happens on the faster machine, so I feel it's using WebDAV to access the share. Now I disconnected the network drive and reconnected again and now it's fast on the laptop. However, if I reboot all is back to slow again. This is driving me mad! Any ideas why it seems to be using webdav for network share access?

Found a bit more. The WebClient windows service is started when I try to map a network drive. That is the service which supports WebDAV. If I stop and disable the service, I cannot map network drives any more from the failing machine. The working machine has the WebClient service as manual but not started and it has network drive mappings to the NAS. It may be that I have installed something on the one failing machine that has stuffed up how it's working, but not idea as yet Any suggestions would be most welcome Thanks

Hi, According to your description, I found that it is very strange, to access the NAS should use the SMB protocol ranther than WebDAV service. The service is used for the following. http://en.wikipedia.org/wiki/WebDAV I suggest to change the startup type of the WebDAV service to disabled for a test. Also, you may use the Process Monitor to monitor the explorer to see whether it involves the service to run. In addition, to use the Network Monitor can also capture the packages after the service running, this can help you know what detailedly happen to this service.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.