The modem's internet light is on and Windows detects no problems with the network. I don't believe our firewall is interfering, and sometimes the internet works perfectly fine. I also don't think it's malware. Neither AVG or Spybot are picking anything up. We do use Bsafe Online, so it could be a conflict with that, but I don't think it is. My personal computer did the same things without Bsafe about a year ago (it's in old messages by me on this forum) and it just went away for no apparent reason.
One user may log on and have no problems for extended periods of time, but then if we switch user (or logoff) the next may or may not have internet access. Usually if we hop around user accounts or restart the computer enough times we'll hit on one account that does work, but that's obviously not a good solution.
One of the odder symptoms is that sometimes the internet will work just fine for a few minutes and then if we leave it alone for a while, like in writing a long message, it'll stop. And then display all of the other oddities.
Pinging works just fine in such states. Other internet based programs do as well. For example, Google Talk works and Spybot ad AVG can confirm no new updates are available. But not the browsers. Firefox 3 gets hung up "waiting for www.google.com" indefinitely and IE 7 is "Connecting..." with "Website found. Waiting for reply..."
And even that's not completely black and white. Sometimes page titles load, maybe even a text box, but very little more. As I was writing this (offline), it stopped and pinging google.com worked fine, as did Google Talk, but Windows Help and Support couldn't get through.
It's highly annoying and I can't figure out what's with it. Hope some good ideas are out there.