got weird NIS Installation alert today -- is it real?

Hello!!!

It said, essentially:
"NIS installation!
Alert (on orange stripe background)
A problem has occurred that needs your attention:
This product is not compatible with this computer’s Operating System. You must have one of the followg Operating Systems:
MS XP (32 bit) w SP 3 home/prof/media center(?)…
[List of other ones…]

Go to technical support website."

I do still use XP, though I’m not sure I have SP 3. Could still be on 2.

I tend to worry about fake things on the Internet, so does anyone know, is this alert real? And does anyone know whereabouts on this (lovely and large!!!) technical support site I should be visiting?

Perhaps I should not have closed the warning. Oh wait! I didn’t, I had notepad running and for whatever reason, the system crashed right after that - the screen went royal blue with some MS-like gobbledygook on it, so I re-started (which is what I call it when I hold down the PC’s power button … though that may not be the proper term). I don’t recall getting such an installation warning before, I’ve been using NIS and XP together … well, forever, in computer terms. So I worried.

It seems fine now. But, am I supposed to do something?

Thanks for any and all suggestions!!!