My browser can't access Google, Wikipedia or Youtube directly

[levithorn627]

for the past few months I've not been able to use the sites
www.google.com
www.wikipedia.com
www.youtube.com

on any web browser, Mozilla and IE being the most common that I use. No other site seems to be affected. I can view them through various proxy sites, but the reduction in speed is quite a problem, particularly with youtube.Whenever I do try to access these sites I receive a Failed connection message saying (among other things) "Though the site seems valid, the browser was unable to establish a connection."

So far the only attempts I've made towards repair are a Norton Antivirus scan, an AVG scan and a Symantec Qhost removal which came up with nothing.

Does any have any advice on what I could do to fix this without reformatting my hard drive?

[tedster]

I'm a bit at a loss here - is this a problem in all browsers, or just Internet Explorer?

[Chris_R]

Have you checked your hosts file?

[tangor]

check your internet security levels, particularly in IE as it also affects FF. Reset to MEDIUM and make sure you have checked your blocked sites to see if by accident these sites were marked bad.

[penders]

It might be worth checking the MTU (Maximum Transmission Unit) setting on your machine. Not sure why this can effect some sites and not others - but it certainly seems to. A friend was recently unable to access hotmail.com until changing the MTU (machine / router)!

check your internet security levels, particularly in IE as it also affects FF.

Really?!

[levithorn627]

Tedster- the problem is with all browsers

Chris R- How do I check the host file?

Tangor- The internet security levels seem to be fine they are at medium and there are no blocked sites listed.

Penders- I'm not sure how to check the MTU.

I'll add a little more information. I live in a dormitory so I don't have direct access to a router but my roommate is able to go to all of the sites that I can't reach.

Also when I attempt to load one of these pages it shows it as done on the the bar below the screen (that one that shows where a link leads to).

I hope that helps

[tangor]

Hosts file is located /windows/system32/drivers/etc/hosts (no extension)

Edit with NOTEPAD. Should have instructions at top of file.

[tangor]

@Penders

Link between IE and FF security was revealed some months back during an IE 7 security update. IE fixed it...broke something in IE AND FF for some sites... and IE was "fixed" again (quickly). Whether that condition (link to system layer security) still exists I do not know...but it doesn't hurt to check both when these things happen.