I have bought a second hand computer with win xp home edition. my older pc had win ME, bought Win XP professional, installed and activated on it. Now how can I use the same win XP professional disc on my "new" pc as I want to discard my old one.

If you purchased a retail copy of XP Pro and intend to scrap/delete the operating system from your old PC then you are quite within your EULA rights to instal it on the new PC and activate it again. You may need to telephone Msoft to activate but maybe not depending on how long ago the original activation was done. I used to have a signature but it disappeared and I just couldn't be bothered writing another so please feel free to ingore this.

Richard59, I like that answer! IN THE MATTERS OF STYLE, swim with the current; in matters of principle, STAND LIKE A ROCK Visit Computer Vitals For A Pleasant Surprise

... depending on how long ago the original activation was done. ... 90 days I believe is the time limit. After that you start all over again. Stuart

The time limit is 120 days from last activation. But, that doesn't mean anything with the new verification proceedures. Although the verifications for updates can be shut down, RUMOR has it that the verification process resets the time every month that the updates are installed. How true this is ...I don't know as all my applications are legal... IN THE MATTERS OF STYLE, swim with the current; in matters of principle, STAND LIKE A ROCK Visit Computer Vitals For A Pleasant Surprise

You're absolutely right, my friend. Question: Is it true that WPA resets every 120 days? Answer: Yes, it is. Every 120 days, WPA will audit the hardware listed above and generate a new HWID. Effectively this resets the changed hardware count to zero. This means that if you change say four components on the 119th day after the last HWID was generated and reactivation was not triggered by that change, then on the 120th day, you can change four more components without needing to reactivate. Source i_XpUser