document could not be registered

[sl.robinson9]

For some very strange reason the following problem just started happening in the last day or so. When I open MS Word (2003) I get the following error message: This document could not be registered. It will not be possible to create links from other documents to this document." I have tried system restore and detect and repair function but nothing works. when I try to repair the application, the Windows installer starts but then gives the following error message: "The Windows Installer Service could not be accessed. This can occur if you are running Windows in safe mode, or if the Windows Installer is not correctly installed. Contact your support personnel for assistance."

So I can't reinstall the software. What do I do to fix this?

Steve