3 seperate things to try
try emptying your 'temp folder' click here (I'd do this anyway)
Repair Office: on Help drop down menu
Workaround: Open My Documents and select the file, copy it, paste it back in and change the file name. Make sure you can open it okay, then you can delete the original.
Also have a read of this: click here;EN-US;211632
( support.microsoft.com and put 211632 in search box) in case link hasn't pasted right :[
....how Microsoft Word for Windows creates temporary files. ... printing, or review, Word creates a temporary file with a .doc file name ...