The below HP ad is MISLEADING.
Just because Windows XP support has ended does not mean that you should upgrade your laptop. If your laptop works fine then what you need to upgrade is your OPERATING SYSTEM. Minimally go for a Windows 7 or Windows 8 upgrade . This can be done by buying a genuine version of Windows from Microsoft and then either installing it yourself or getting it installed from your local technical support guy.
Although in future HP support might not entertain your support request for this laptop because you did something terrible which they did not permit but i guess that would be a small price to pay as you save some money by not upgrading your perfectly working laptop.