Rootkit

Microsoft's monthly software update informed me that my old laptop had a Trojan or "root-kit" and offered some choices. I selected "delete", maybe unwisely as root-kits can be troublesome to remove, hiding and re-creating themselves when you think they are gone. Assuming it was real, how it got there is a mystery, as I verge on neurotic about the internet, and no other scans had shown anything untoward. Proceed with caution.