Using a Windows 7 Dell E5510 laptop connecting to a couple of Windows servers. One is Windows Enterprise Server 2007 Service Pack 2. It connects fine. Server with the problem is a Windows Server 2003 R2, Standard Edition Service Pack 2. Folder on the server is mapped as a network drive on the laptop. My user profile is Administrator on all machines. Using Word or Excel 2010, it takes forever to get a file to open or to save a file. When opening an excel file "Trying to connect to U:\xxserver\my user folder\specific folder Press esc to cancel" pops up, then goes away, pops up, then goes away, pops up goes away.... until the file finally opens. During this process, the top of the excel window shows Excel is "not responding" which comes and goes like the pop up message.
Similar response when using explorer, but usually not quite as slow.