Possible intrusions

[fourteen85]

whilst on the intenet this AM I have gained a red circle with a white cross in it. It says in a 'balloon' that it is from windows security center and my computer is in danger as it is infected with spyware and I should click it to install latest removal tool. I have been on windows website for latest up dates and there are none available, I have scanned with Avast, defender and spybot but all say my computer is running normally. a bit of a long shot but anyone any idea what this might be.?
The only other thing out of the ordinary is a download box appearing when I boot up from Kernals8.exe asking if I want to load ,could this be related

[fourteen85]

I should have said that the red circle has appeared on the lower task bar

[vehelpfulguy]

I just did a search on "Red circle white cross" in Google and found loads of hits.

Not sure if any are yours, but have a look at them.

[Ralph]

Sounds like a scam. They talk about a very similar thing here. There is also a page linked to there (I think my computer is infected or hijacked. What should I do?) that provides comprehensive steps to attempt removal of the suspicious stuff that may be causing this.