Auto updates off. Error number 0x80070424

Hi all,
My security center on Windows XP show that automatic updates are off and won't switch on but when I view through system settings it is displayed as on.
I have been through the MS site and Mr. Fixit and performed all of their suggestions to no avail.
My antivirus software is switched off,so it can´t be that.
This all seems to have started when I was alerted to a possible Trojan on my system. I followed all the safety precautions and the problem was dealt with, or so I thought!
I am new to this forum so sorry if unclear I hope one of you good people can help me.
Thanks
