BleepingComputer.com: Windows XP will not Update - authomatically or manually

Windows Security is telling me my Automatic Updates are off and I am unable to turn them back on. I get a message saying to go to Systems in Control Panel to change setting. However, in Control Panel Auto Updates are already on.
Tried turning off auto updates in CP and attempting to install manually with no luck. A few other screwy events but trying to stick with one problem at a time as mod suggests. Tried reinstalling IE8 (not sure why) but no change.
Running Windows XP. I am NOT computer savvy so any suggestions need to be spelled out step by step - even the seemingly obvious ones.
I have run Malwarebytes and use Avast Antivirus and MS Security Essentials. A long time ago I ran a program called Tweak now registry cleaner. I confess to being the click-happy and ignorant user in the chair that probably created my problem myself in an effort to keep my PC secure.
Thanks for any advice.

security center reset

This post has been edited by cogs10: 21 June 2011 - 06:34 PM

Isw27, which WinXP? Home, Pro, Media Center, etc.? Have you installed Service Pack 3? You need to note that the link provided by cogs10 is a four year old thread and there have been many changes since then, including Service Pack 3 being released.

According to your post, you are running MSE and Avast, two anti-virus programs which will cause conflicts. You should remove one or the other. Or disable Avast to see if that is causing the conflict.

Rosie