MS Access 2007 - Cant find MSAIN900.dll

Hi
When I try to start MS Access 2007 on a Vista computer I get the message
"Can't find language DLL MSAIN.DLL" and access fails to start.
I have repaired the office installation etc - no effect.
I have several other versions of Access on the computer and they must stay
and all work ok.
Any ideas as I am desparate.
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PhlipC