We have the same problem where I work, solution I found was to log onto the machine as Domain User Full Access rights not Local Machine Admin. Then install Office 2000, once installed run Word, Excel etc. Click OK to any messages. Then once you have done this then log onto the machine as the user and you should be able to get into say Word without any messages appearing.
You might also want to consider when installing as Domain Admin that you select to install all options for MS Office, like the Organisation Charts, Filters etc. This will take more room on the hard drive, but then elimates the chances of a message coming up saying insert CD to install this feature or select network path etc.
When you install you might also want to consider copying the CD to the machine and installing from the hard drive, rather than a network drive or CD drive. Especially if you have shared a CD drive just to install Office on, as this could be a problem in the future when say Word needs to install a feature but cannot find the mapped network drive you used when you first installed. Good Luck!!