selected users on IE8 can't access web site but can with Firefox

Check to see if checking or unchecking Compatibility View helps. You can find it under the tools menu in IE. Sometimes there is an icon in the address bar.

IV

Did you try resetting Internet Explorer Settings

Windows key + r

Type: inetcpl.cpl -------> click on "Advanced tab" --------> Under "Reset Internet Explorer's settings to their default condition.  Click "Reset...."

In the Reset Internet Explorer Settings dialog box, click Reset.

Click Close and then click OK two times.

Are the Windows XP system upto-date with Microsoft patches?

Sudeep

You may also be able to access the site by going to IE, Tools, Internet Options, and Security tab. Click on Trusted Sites and add the site there.

.... Thinkpads_User

In the last couple of years there have been quite a few "Root Certificate" updates.  They are 'Optional' updates and must be downloaded and installed to keep the security certificates up to date.  If the site is asking for a cert that is newer than what the computer has, then they will not be able to connect.

Firefox has it's own Root Certificates but IE and Chrome use the Windows system certificates.

There was another post about a newer version of IE not accessing sites and the user solved it using Trusted sites as I noted above.

.... Thinkpads_User

I don't believe you can make it a Trusted site without having an SSL/TLS cert that works with that site.

Thanks everyone for you suggestions which we will investigate

the problem is becoming more intriguing as we have done further investigations and the results are as follows.

We have  a live and demo site hosted by 2 different hosting companies with supposedly identical setups and web applications. Only difference being different firewalls and the live site having a SSL EV certificate and the demo site a normal SSL certificate.

IE8

User A -> Live site -> pages don't load. sometimes works after pressing F5 refresh

User A -> Demo Site -> OK

User B -> Live and demo site OK

Firefox Works fine fine for User A on live site.

What possible settings could cause this inconsistency?

Thanks

Look in the lower left corner of the browser window and see if there is a yellow triangle that indicates an error.  Click on it if it is there to read what the error is.

We have finally tracked down the problem by sending one of our guys to the client. When we asked them to turn off the anti virus it worked perfectly.

It appears that there is a setting in McAfee which does script scanning on URL. Once this was turned off, our site worked perfectly.

Very frustrating after diverting a huge amount of resources to this problem!

Congrads!!!!!

Brilliant solution!