Thanks for your brief summary about your issue, Please try to unistall any existing version of different security software from your computer and then try to udpate your McAfee security software. That should be able to resolve your issue.
If still unresolved, please run MVT from here : http://mvt.mcafee.com and post me with your session id number.
I also have this problem and it's gotten much, much worse. It started when Real Time Scanning wouldn't stay on, then I kept updating McAfee and running the tool posted with the FAQ, restarting each time. BTW, this was right after McAfee told me it caught 2 Trojans. After a couple of days, it finally seemed to work. But, I started getting popup windows that I've never gotten before. Then, the problem came back and got much, much worse. I tried to run a scan with my updated McAfee, and it gave me an error message telling me it had encountered an unexpected error. Then, I restarted the computer thinking that might kick-start things, and as I logged on, the computer told me it was installing something called Sunlight, and gave me a RUNDLL error that included the last two lines of the last email I wrote. Not a good sign.
Tried to run a scan and it failed again with the same error message. Tried to update McAfee, and it said it updated, but it still wouldn't scan. Now it won't even update, nor can I get the McAfee help to come up in IE - just says it can't display the page. I tried to download and run (following all the proper directions) Stinger, but it gets through one or two files and hangs. Then when I try to stop the Stinger scan, that process hangs and I end up killing it using Task Manager.
I can't get any IE page to come up at all now, and am writing this on my laptop away from my home. I'm certainly happy I don't have a home network, or this thing would be infected too.
The computer is an older Dell (circa 2002) running Windows XP, with a Verizon broadband connection (there's no high-speed in my neighborhood). I've had McAfee on it from the start, and have always updated Windows and McAfee automatically. Obviously, some sort of virus has infected my machine, and I'm pretty puzzled as to how to proceed at this point if the McAfee service I've been paying for (for many years) has been corrupted as well. I did PM Dinz a couple of days ago, before my computer was effectively shut down, but have not received any reply. I'm not happy at this point.