Windows shield remains on taskbar

Hi all,
I've had a PC for over 4 years now but have described myself as a beginner because I'm still naive about them. This is my first posting and I'm amazed that I have only just discovered this site.

My problem: The windows shield was there on my task bar yesterday evening and placing my mouse pointer over it revealed,

"Updates are ready for your computer click here to install these updates. "

I did, and the shield kept reappearing still giving me the same instructions.

The download is for, Security update for microsoft XML, core services 4.0, service pack 2, KB936181.

Because it kept reappearing I kept installing, needless to say I have installed it about 7 times.

So if it's installed correctly does anybody know why the shield is still on my taskbar and still telling me,

"Updates are ready for your computer, etc. "

Grateful for any advice. Thanks in advance.

 

Pete,
Thanks for your advice. Problem easily solved as a result of you pointing me in the right direction. I've no doubt I will be back for more of your much appreciated assistance. Great site! Lots of stuff to read.

Cheers,
Tony.