From a few readings that I did on the 'net gpedit.msc is not part of the Home version of XP. I copied the following for you but only as for your information and NOT as a suggested step for you to take:
GPEDIT.MSC (Group Policy Editor) isn't available on XP Home Edition, partly because XP Home cannot join a domain by design. Although the took is designed to be used in an Enterprise environment running Active Directory, all it really does is making registry entries. So, the best alternative is to edit the registry using Regedit. Be aware that editing the registry incorrectly can make your system unbootable or cause other issues, so proceed carefully before diving in!