I am having trouble with opening some web pages on some of the computers in my company. We are on a Win NT 4.0 SP6a and Win 2000 Professional computers. Two days ago they were accessing the sites fine, but yesterday the sites went down and then it stopped working after the sites came back up. I have ran a virus scanner and nothing is there. I have acquired all possible updates available. The company that designed and runs website says nothing has changed and they have had no problems with the site, nor the company. Any ideas on what can be the cause of this?