Oh Boy, I really did it this time…

I kept getting a “you are not using a genuine copy of Windows” error whenever I booted up my
ancient Tecra 8100. It had Windows NT/Win2000 on it, apparently bootlegged from somewhere, (My older son’s pc). So I installed my “real” WINXP Home on it thinking that would solve the problem. Now, I cannot access the internet, my 3 com ethernet controller disappeared, I’m getting OS conflict messages, etc. etc. Is there a way I can get my “bootleg” copy back and restore it to the way it was? What a mess! Hope someone can help!!