acetnt,
I don't think you understand, I'll try'n make it real simple {sorry to confuse ya}
If you have a Microsoft Windows XP Home license on your Emachine you can use ANY OEM or RETAIL Windows CD you wish!
The componets you change in your system have nothing to do with reloading the O.S. {which you have a license for} The ONLY thing that concerns Microsoft is that you have it loaded on only ONE machine. PERIOD!
So change what you want, install whatever BIOS you want, upgrade your heart out :}
As long as you don't use someone else's license, your fine & legal:aok
Any questions, lemme know.