I've just had a run-in with deactivation of Windows XP due to "significant hardware changes since the copy was last activated". But, since I installed XP, the only thing I did was remove 512MB of RAM in the laptop, and install 1GB of RAM. I also plugged in the USB mouse during the bootup.
What probably triggered it, however, was changing filesystem of the system partition from FAT32 to NTFS using Microsoft's own convert.exe, included with Windows. I have no idea where they're pulling out the idea that filesystem of
root system partition is a hardware thing.
I have no idea if this reactivation ate one of my activation slots for this product key, since Microsoft's Knowledge Base link on the subject appears down. I surely hope I won't have to deal with tech support; I've heard they're friendly and unintrusive in Croatia, but still…
(By the way, unusually for tech-savvy Croats, this is a legit copy. From MSDNAA and FER, of course 🙂
Since there's no way I could have captured the messagebox that appears during login (this isn't a VM and I don't have a good camera) included is just a leftover shot of WGA, after repeated activation.