I'm currently googling for an answer, but how do you repair an Office installation on a Terminal Server? It says something about not being able to repair on a TS in operational mode...

Do I just need to stop the TS service?

I'm not sure of the answer myself, Dave, but may be worth asking on either Super User or Server Fault. (Can't decide which'd be more appropriate, either - sorry!)

Thanks Edd, I'll give them a look-see.

I'm beginning to hate Google! Whenever I do a search on of the top answers looks promising, but is always an "ad" page for ExpertsExchange.com, which needs a hefty subscription!

The two sites I linked two are set up and run by Joel Spolsky and Jeff Atwood, and are Power User and SysAdmin versions of their Stack Overflow coding question-answer site. SO itself was set up because of their frustration with using ExpertSexChange (Although it has now had a hyphen added to its URL (they often refer to it as "The Hyphen Website" on meta.stackoverflow.com)) and PHPBB-style forums which are designed more for discussion than Q&A.

Just click on the "cached" link in google & scroll to the bottom.

To repair Office on TS I'd recommend putting the server in install mode

Note To determine the current mode on the Terminal Server server, run the change user /query command at a command prompt.
Click Start, and then click Run.
In the Open box, type cmd, and then click OK.
At the command prompt, type change user /install, and then press ENTER. The following message appears:
User session is ready to install applications.
Type exit, and then press ENTER.
Add or remove the programs that you want.
To switch a Terminal Services server into Execute mode, follow these steps:
Click Start, and then click Run.
In the Open box, type cmd, and then click OK.
At the command prompt, type change user /iexecute, and then press ENTER. The following message appears:
User session is ready to install applications.
Type exit, and then press ENTER.

Thanks Saspro, I'll give it a try tomorrow.

It took longer than anticipated - our supplier was supposed to deal with it, but they haven't lifted a finger, so I finally took the server offline at lunchtime and did it then.

Turns out that somehow the VBA support in Office had been de-installed!