Windows XP is a desktop operating system. As such, it is not intended to run a full-blown database server like SQL Server. For development and/or testing purposes, you can use one of the following versions:
So, if you are attempting to install Standard or Enterprise Edition on Windows XP (or Windows 95/98/2000 Pro, for that matter), you should try to obtain one of the above editions for use in that environment.
See
SQL Server System Requirements for more information.