Hello, I am a member of a SharePoint Enterprise 2010 group and recently a co-worker and I installed Office 2010 on our machines to explore the co-authoring features through the 'document library' web-part. When the second user attempted to use the file he was prompted that the file was in use and he could open only a read-only version or edit the document and update changes when the other uses closes the file. Could anyone provide me advice on why this was happening? My impression was that co-authoring was enabled 'out of the box'. If this is an administrators issue could someone provide me some guidance or good questions to ask as this is a recent deployment.