Confused... web site issues on 2 out of 3 PCs

All three PCs were fine on Friday, but on Monday this started to happen.

Happens with IE and Firefox. Some web sites will not open. For example AOL.COM is fine, but if you click on MAIL on that site it will not open the page - it will just go to a blank page and spin. Several other pages that require login do the same thing - they are industry sites, not big name things like hotmail or anything. One on of the machines I was able to download and install logmein (which is a secure site) with no problem. I did that both so I can get in over the weekend and keep trying things and to test a totally different site.

I had the two PCs in my shop and the sites worked fine.

They went back to their location and it doesn't work.

We reset their router to factory, no change.

And, of course, the third PC works fine with all these sites. The only real difference that I can see is that the two non working ones are using Windows 7 and the working one is XP. All are set to DHCP.

I tried manually setting the DNS server to OpenDNS servers, no change. I reset IE (even though Firefox didn't work and a second PC didn't work) and no change. I checked the HOSTS file even though that wouldn't make sense because it worked at my shop.

I may have left out some things that I tried, but I think that's it.

I'm out of ideas on what to look at next. Any thoughts?

Oh, a full AV scan was run on both machines. Both with the Kaspersky Rescue CD and Malwarebytes AntiMalware. There were a few little spyware programs, but nothing major and nothing that was the same on both machines.

1) It's a modem / router combo

2) Router was reset to factory so any filtering should have been cleared, right?

3) Westell something or other... I can get that if you think it will help

4) I disabled IPv6 on the workstations, no change.

Yes. The router shows the 3 PCs (as DHCP clients) and they all have different IP addresses.

I agree the router seems like the culprit, but it if is, why does the XP machine work just fine?

I can test the cable question pretty easily, actually. The machines are wired, but they have wireless in them. Right now wireless is off (they were connected with both and I thought that might be causing trouble) but I can turn it on and disable the wired NIC.

I don't have any easy way to swap the router. It's a DSL modem with router built in supplied by their ISP. If it was just a router I could use a tester that I have.

And, to be clear, I did not change the DHCP server. I did manually set the DNS, but nothing else. Can't think of any reason that any other part of the DHCP server would matter though.

1) Maybe... but I only have remote access right now and if something goes wrong I won't be able to fix it

2) I'm not sure that's even an option with this model, but I'll look into it

I had a similar problem before. I switched to Google DNS (8.8.8.8) and that fixed it.

Something went wrong... I don't have remote access now. Don't know if the machines were powered off or if there is an Internet issue. Nothing I can do until someone shows up on Monday.

They've always been the same. Considering it is only some sites that have issues I think a port problem is very unlikely. However, once I can get into the systems again I will be trying wireless which will eliminate the ports as a potential problem.

You need to isolate it to the ISP connection, or the PC itself (settings, software, etc).

I would take one of them to a known-good net connection somewhere else and try it

does the problem occur when only one machine is connected?

Another thing I am thinking of.
The router isn't functioning as a proper router, it put all 3 PC's in a DMZ? The first PC (Which was the XP?) will be authorized by the Modem and the other 2 are not?

I'm reaching a bit, but that's all I can think of, it's the router.

Put a 2nd Router BEHIND the first one and see if all 3 have problems. The 2nd router should mask the 3 computers and the 1st router will only see 1 computer accessing.

I'm hanging on here for an update minidrag. Its like a suspense novel. Can you make them a priority customer?

I want real-time streaming updates - audio and video. All of FW Tech will be there with you, IMing and texting advice

If you wear your cape and mask, then video is permitted

Glad it worked out minidrag. Hope we helped you prepare and troubleshoot

How long were you out there? Were they impressed? Or is it just that they expected for you to solve it easily?

Now I'm sad
I gave Mini the answer and I didn't any green..hahaha

I miss this thread. I felt like I was playing "Stump the Chumps"

Minidrag,can you create another one?

minidrag said:   I almost did, earlier today. I got in a machine that had been infected and the home page of IE kept going to "Welcome to nginx" and I had a heck of a time fixing it. Almost posted here for help, but I finally got it cleaned up.Drat!