I am currently working on a dual boot machine that boots to WinXP or Win 7. In Win XP, all my documents open correctly in Compatibility Mode - I can save and edit them without problems.
In Win 7, however, all my .doc files open as "Read Only." I cannot save them. I have gone into the Trust Center and unchecked all the boxes in the "File Block Settings." There are, however, some settings such as "Word 2003 Binary Documents" and Templates and "Word 97 Binary Documents and Templates" that do not have a check box to uncheck for "Save" so there is nothing I can do about that. If I create a new Word document, however, with the .docx extension, it will then let me edit and save the document.
I have gone into the "My Documents" directory and done the elaborate security thing where you take ownership of the files so that you can change them, but this hasn't helped. They still open as "Read Only." All these files are on my hard drive - they are not on a network. I have created all these .doc files and they are not accessed by anyone else. All the files are being opened in Word 2010 - the only difference is the OS I am opening them in.