Fifefox: 1 computer opens website other can't connect?

Basically Ive seen this before when proxies become enabled and it won't let u access internet. But here's what happens:

Some big websites, like downloads.net, or some microsoft websites are just "unable to connect" as if there's no connection.

I tried to get on my laptop- and used same browser, same websites, and it opens the websites no problem.

I tried cleaning the browser folders, cache etc, setting is on "no proxies or w/e". Internet works, I can still access some websites no problem. But some its giving me the offline/unable to connect screen... What should I look into?

The problem websites, do they open up in other browsers installed on the affected computer (EX: IE, Chrome, etc)? Yes/No?

If yes, go to the start menu, find the 'Firefox' folder entry under 'all programs'. Click the 'Firefox safemode' entry, then put a tick in disable all addons and then click continue. Try to brows to one of the problem websites. Does the website load now? If yes, one of Firefox's installed addons is causing the problem.

If they don't load in other browsers: Ping these problem websites via the command prompt.
Start menu > type cmd, hit the return key, then type ping downloads.net

Does it ping successfully or time out?

If the ping is unsuccessful try flushing the DNS cache via the command prompt (the command: ipconfig /flushdns

romanteni said:

Basically Ive seen this before when proxies become enabled and it won't let u access internet. But here's what happens:

Some big websites, like downloads.net, or some microsoft websites are just "unable to connect" as if there's no connection.

I tried to get on my laptop- and used same browser, same websites, and it opens the websites no problem.

I tried cleaning the browser folders, cache etc, setting is on "no proxies or w/e". Internet works, I can still access some websites no problem. But some its giving me the offline/unable to connect screen... What should I look into?

Will try when I get home. I only have firefox and IE, but I HATE IE with huge passion, shit even freezes while starting up. lol.