Experts, I am having a problem I am just stumped on and need some help. Installed a new Dell Optiplex 390 (realtek NIC) on a customer network and Internet Explorer, Firefox, etc. work fine. However, when malwarebytes tries to update it times out, when I try to install Windows Live Messenger it times out, and additionally, other programs do the same. It seems only browsers work. I have unchecked the proxy setting and honestly tried everything I have read or could find in forums and on the net. At this point the machine is a virgin install of Windows 7 Ultimate (I thought maybe Pro might be the issue or the OEM install) and there is NOTHING on it by all Windows Updates and of Malwarebytes (which is my testing tool to see if the problem is solved). I can take the machine home or put it on any other network and it works like a champ. I have already consulted Cisco about the router and switches and they can find nothing on why this issue is happening. Bottom line, I am stumped. I am seasoned professional and will no doubt feel silly when a solution is offered up I did not think about. However, I need help and fast. Thanks in advance!