Hyper-threading? With SMT you will have two threads with each core, so they show up as two extra "cores".

I work IT for a US university, and I've got a call from a professor who seems convinced that her machine is "only running on one core". She claims that when she uses MATLAB, task manager shows it ...

Task Manager is a Windows tool everyone uses at some point, but there's quite a high ceiling to what it can do if you want to learn the ins and outs of it. What's merely a task killer for most users ...