I have a 6 month old Imac (2012) running Mountain Lion. I have installed Office for Mac 2011. I have tried to save a Word document and get a message saying that Word cannot save it as the disk may be full or write-protected. I have over 1TB free space on the HDD and a check has shown that there is no damage to it. I have certainly not, knowingly, set up any form of security in Office as I am the sole user. Has anyone any suggestions please as to what the problem might be. Thanks.