Cannot view some [high security] sites!

[sqdge]

I know that this type of post has occurred before - and I have tried (nearly) everything that previous people have suggested, but I can not get it to work.

I am running XP SP2 on my hp laptop. In the background I have Spybot S&D, Norton Antivirus, and Norton Personal Firewall. I access the internet through a WLAN. The other computer on the WLAN does not have this problem.

My computer won't access certain sites. I have noticed (as other have in the past) that these sites tend to involve a heightened sense of security (Microsoft, Symantec, other anti-virus sites). I have tried a number of things to solve this:

• I checked that PCT 1.0 and TLS 1.0 are unselected under Internet Options
• I have done the regsvr32 thing and made sure a whole host of drivers were present and correct
• I have compared my HijackThis log with other people's and found that nothing matches
• I have made myself a cup of coffee, restarted the computer, and seen what happens

The problem happens on both IE and Firefox, and is not a problem with either spybot or Norton Anything (I have disabled both at times to see what would happen).

Any help would be gratefully received.

Thanks.

[sqdge]

I would like to say that I have solved it. And now I will dispense the advice to anyone else with the same problem. Firstly, you have to look at what kind of sites you can not access. It took me a while - but eventually I realised that it was only sites that gave anti-virus software away (including the Microsft site).
So, after spending days on Google, I found the solution is in the 'hosts' file:
C:\Windows\System32\Drivers\Etc
Open up 'hosts' in notepad and hopefully you will see a long list of addresses that you couldn't access - delete these (do not delete the one at the very top called 'localhost')

Hopefully, that will solve the problem.