Ross, one of my clients was having a heck of a time trying to make sense of "CoInitialize" Automation errors in VBA. It happened in VBA commands for Page Setup. He had enlisted professional help in uinstall and re-install of Office. I thought about it and wondered whether Excel was behaving like Word - the existence of a proper printer setup is vital for these programs that need to calculate Print Previews or even calculate document line width and page rendering when they work. He reported back that this was indeed the case.
Whether you are using the Windows machine for long term or for a short teaching stint or short development / testing gig, make sure you install at least one good printer driver. Sometimes a light weight driver like a free Acrobat driver isn't even good enough.