Computer Cleaned, still cant access windows update

Hi, I have removed some malware from my Windows XP home sp2 machine. It seems clean but I still cannot access windows update, or any major virus company web sites. My hosts file is clean, but still nothing.

So far I have run Malwarebytes, spybot s&d, super antispyware, hijackthis, and avg all in safe mode. Originally I couldn't get into safe mode, but I used a safeboot registry add to get it to work.

On top of all the scans I have run SDFix, ATFCleaner, and combofix all per instructions on other posts.

I have updated all my antivirus and malware/spyware software manually and it is up to date. (Icouldnt update any other way because the update sites are blocked)

Thanks for the help. I have worked with computers for many years and rarely stumped like this.

What happens if you turn off your firewall? Can you access the sites then?