Because Windows XP is a copyrighted Microsoft product, bypassing the activation code makes your installation of the operating system a counterfeit copy. You must acquire a legitimate activation code and enter it when the operating system asks for the code.
Microsoft has dropped all support for Windows XP and no longer sells the operating system. Users must buy Windows 10 instead, or buy a Windows 7 license from a third-party vendor such as Amazon and upgrade it to Windows 10 for free. Once upgraded, the new Windows 10 license belongs to the customer and is not different than a separately purchased license.
When you buy a license for and install Windows 7, it automatically downloads the Windows 10 update. The system displays a notification on the taskbar once Windows 10 is ready to install. Although most of your Windows XP applications should work on Windows 10, you may need to use the built-in compatibility mode for some applications. To do so, right click on the application, select Properties and navigate to the Compatibility tab. Check the Compatibility Mode box, select the Windows XP version you used and click OK.
Using a counterfeit operating system counts as software piracy. As of 2015, individual offenders can receive fines up to $93,500 and five years of imprisonment; fines go up to $467,500 for companies. Civil penalties may also apply in the forms of compensation of financial damage caused to Microsoft in lost profits and court costs.