Toughbook CF-31 Win 7 Ultimate CF-30 Hard Drive Compatability

I am upgrading to CF 31 from CF 30. Took my relative new 300 gig CF 30 hard drive and placed it in the CF-31. To my surprise it booted up and worked!! It has Win 7 Ultimate on it. A few things don't work like the Wi-Fi and network cable port. I have drivers I believe for those. My question---I thought that windows 7 was tied to a particular hardware. Shouldn't I get a Microsoft warning that the hardware has changed and to either reinstall the operating system or call a Microsoft number? I...

Toughbook CF-31 Win 7 Ultimate CF-30 Hard Drive Compatability