Tengo una base de datos e Access que contiene una serie de documentos Word y PDF.

Unfortunately, this sounds like possible corruption in the accdb where the Word docs are embedded in attachment fields. Either that or there is a problem with the Word installation on that computer.

The first trouble-shooting step I would try is to reinstall Office on that computer.

Also, you should understand that embedding Word docs and PDF files in attachment fields is not a best practice. Rather they should be stored external to the accdb, in a shared folder on your network. Store only the path to those documents and files in the table in Access and load them externally.