IE unknown popups

While using IE, my client gets popups appearing at random times. These are not from the sites, but something locally seems to be initiating them. The content of the popups are random. First it was a dating service, then a mortgate place, pc support, etc. Any suggestions on how to track down and eliminate? Looked in the task list and it only shows IE. looked at the tasklist /svc that was posted and everything looks good.

Thanks