I've gone to the folder. It's the OFFICE12 folder. I was wondering if anyone knew the filename because there are about 50 different DLL's in there.

After more Googling I believe it's the MSO.DLL file.

I want to know which one it is because I'm debugging a weird problem on one of my computers. I have 4 computers at work and a macro I've written works on 3 of them. The 4th one generates runtime errors whenever a chart is created. It's as if the charting library isn't there. I suspect there has been either a registry error or a corrupted reference file on the machine. So I want to restore the reference files back to their original ones from my MS Office DVD.