It is illegal to run unlicensed sw on any OS. The message is often shown when u use crack or like other illegal sw to overcome the 30 days evaluation or trial period. Though I am providing the solution that u made it by mistake.
To avoid such situation, u must repair the windows xp with xp setup cd. During repairing no software or ur settings are changed. All are intact, but u must download a software to find out the xp cd key / serial key. This sw helps to find out ur xp key just double click the “win key finder.exe” and write down the key, when xp asking for key just supply it and complete the procedure. I provide the link below:
Hope it works for u…..