Office 2000 is no longer supported and is not considered compatible with Windows 8. Compatibility information can be found at the Windows Compatibility Center
and support availability for Office 2003 and Office 2000 is documented here on TechNet
In order to use any Microsoft Office applications on Windows 8, it will have to be at least Office 2007 or above.
More information on Microsoft product lifecycles can be found on the Microsoft Support Lifecycle page
MikeWindows Outreach Team – IT ProThe Springboard Series on TechNetWindows XP End of Support