I have three PCs running WinXP connected to the Internet through one router. Two of them connect to everything, no problem. But the one I use the most, my personal desktop PC, cannot connect to certain sites (sfgate.com, for instance): Firefox gives a "Page Load Error/Failed To Connect" error. So the problem must be in that PC, not the router or ISP or anything else outside it. It connects fine to most sites, like this one.

I've tried using different browsers, changing the MTU, disabling the firewall, rebooting the router, changing the DNS server (to OpenDNS from the default); nothing helps. I'm running AVG, so I doubt it's a virus.

Any useful suggestions for alternative measures would be most appreciated.

Download the Firefox executable Firefox web browser | Faster, more secure, & customizable
- save it to your desktop.

Uninstall Firefox and then delete all folders relating to Mozilla/firefox (if necessary use the Start - Search option)


Reboot.

Reinstall Firefox from the downloaded executable, don't import anything.

report back..

As I mentioned in my original post, the problem is independent of any particular browser (i.e., it also happens with IE), so I doubt your solution would help. But thanks anyway.

I think you're missing my point. I want to install a totally "fresh" browser without any limitations imposed by previous implementations.

In fact go here:

Apple - Safari

download Safari - do not import anything!

Okay, I've installed Safari (apple.com is one of the sites I can't access, so I downloaded the installer on another PC and transferred it).

Same problem.

If you boot into "Safe Mode with Networking" do you have the same problem?

In Safe Mode with Networking, I can access the sites I couldn't before. So what do I do now?