I've got an 11 year old IBM ThinkCentre (from back when they were branded by IBM) running Windows XP SP 3 -- the same OS it had when I bought the computer, although I cloned it to a larger HD in 2007. It's old and I'll be getting rid of it, eventually, and it's not my only computer, but it's convenient and I plan to nurse it along until it drops. I've got it protected by a good firewall, a good antivirus program, and MBAM Premium. Daily scans show it's not infected with anything. I've been getting and running updates from Microsoft on a regular basis.
Tonight, out of the blue, I started getting nags that seem to be coming from Microsoft claiming that my "copy" of Windows might not be genuine and I have to resolve the issue by downloading a "tool" -- WGAPluginInstall.exe -- to validate it. It does seem to be sending me to a Microsoft website.
Does this seem legit? After Microsoft has been updating my system for 11 years without complaint?
Is it necessary? I don't really want to download more junk than I need to.