There are few different options:
1) You can ignore the service pack and the hotfix and continue to run with
your unpatched install of AutoCAD Mechanical 2005. Not something I would
recommend.
2) You can uninstall Windows XP SP2, then install the AutoCAD Mechanical
2005 service packs and hotfix, and then re-install the Windows XP SP2.
3) You can install the AutoCAD Mechanical 2005 service packs and hotfix on
your current configuration. Just be prepared for the install to run several
hours before it finishes.
4) You can contact Microsoft at the number I provided in my previous reply,
obtain the Windows XP SP2 hotfix which addresses the install bug with the
Autodesk products. Once the Microsoft hotfix is installed you can apply the
AutoCAD Mechanical 2005 service packs and hotfix without the need to
uninstall Windows XP SP2 and no long wait time for the installs to run.
--
Mike Dickason
Developer
Manufacturing Solutions Division
Autodesk, Inc.