You can simply install Office 2010 Home and Business. The default installation process will replace Office 2003 and Office 2010 Home and Student, but will retain their settings. Outlook 2010 will be unaffected. A custom installation could be used to retain Office 2003 for use alongside Office 2010 Home and Business.

Alternatively, you could uninstall Office 2010 Home and Student (and any left-over Office 2003 components), then install Office 2010 Home and Business. Since an uninstallation doesn't remove your existing settings, installing Office 2010 Home and Business will preserve your Outlook etc. setup.

Do note that uninstalling/upgrading an Office application has no effect on your data. That said, it's always good practice to make regular backups - especially before making major system changes.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]