My Windows XP no longer updates, but I always have the icon in the system tray and hovering over it gives the message "Downloading updates: 0%".

I presume I must have blocked the updating utility with my firewall, but scanning through the list of blocked programmes doesn't reveal anything obviously amiss.

Does anyone know what process/application I have to allow access for update to work? Cheers

Do you mean update automatically, or do you mean unable to update manually too (ie through the program list)?

First question I would have (after many battles with this) ....can you still access all the control panel icons, and especially the net cons stuff, and their properties?

Even if you cant update auto like, you should still be able to download the individual updates.

Run Spyware / Adware / Virus scanners - some of these little nasties deliberately turn off WU to allow them to exploit security holes.

A friends PC had a similar problem with a naughty little app called SpyAxe recently.