MICROSOFT WORD DOCUMENT RECOVERY
Sometimes large documents containing images files and screenshots, sometimes tends to illogically block Microsoft Word when you try to modify or edit them.
In this case try to proceed as explain below:
Open the document and save it as a RTF file (Rich Text Format).
Close Microsoft Word. This is necessary in order to avoid any malfunction.
Open the RTF file.
Save as using the doc format.
Normally the new doc file should now work properly, though this method is not fully reliable.
To avoid these malfunctions try to use LaTex and have OpenOffice installed.
LaTex is a language allowing the creation of high quality document files. Unlike other text editors LaTex allow the user to edit a document without altering the source file.
OpenOffice is a freeware that regroup a powerful text editor, a graphical tool and presentation software. Use OpenOffice to open the failing documents, make the modifications you want.