Office 2003 Locks up

I am currently running Windows 2000pro SP4 on new wstn’s with MSOffice Basic 2003. I am haveing a daily issue with some not all wstn’s of Outlook and Word when both are running to lockup. You then can kill both programs and it seems to be ok for a while or next day. You can run each sepeartely and seems to run ok. Any ideas or help would be appreciated.