Stupid XP forced me to reinstall my OS

I was reinstalling Windows XP on my laptop today. It wasn't a planned installation but a semi-accidental one. All started with this morning when I was trying to test the VLK Product ID (from my work machine in the office) on my laptop, and I was shocked to find out that it was rejected. In fact, even the non-VLK Product ID from the office was rejected. I was very pissed, and turned out reinstalling the OS on laptop using my VLK SP2 WinXP disc. It worked very well, and now I have my laptop activated (because it's VLK) and able to do all the Windows update including the IE 7. Pretty cool.

This also proved that the kind of installation disc you used to install XP dictates what Product ID can be used by your XP OS environment.

However, I still don't understand why all my other retail product ID failed... I mean, they are legit :-< ....