Trojan alert

Got a small problem. I installed a bit of software that was an update to another program. Now I get regular "alerts" in the form of a toolbar flag up saying that I have a Trojan and I should visit this website http://www.viruslocker.com/ to buy their product to fix said problem.
Having run my McAfee online scan twice, I am of the opinion that this is just a ruse to get me to buy the software. Has anyone got any idea of how I can remove this, it is getting to be more than a little annoying.
Thanks
Matt
Having run my McAfee online scan twice, I am of the opinion that this is just a ruse to get me to buy the software. Has anyone got any idea of how I can remove this, it is getting to be more than a little annoying.
Thanks
Matt