robocall, because it took a few seconds from the time I said "hello" for someone to respond. Sounded like call center environment. Could not understand a single word they said - either they were speaking a foreign language, or they just couldn't speak English well enough to be understood. No idea what they wanted.
Hacker trying to get remote control over my computer by saying they were from "Windows" and received error reports from my computer for 2 weeks and that I downloaded a virus. Oldest scam in the book.