Problems deleting files in Microsoft Word 2010

A Word document suddenly changes into a 'read only' file which cannot be saved or deleted. I have 'saved' under different file names as instructed, but as a result I now have 10 versions of the document, 9 of which I don't want! The 'Help' file says go to 'Properties' and untick the 'read only' box. The boxes aren't ticked, so I still cannot delete. How do I delete these files?

Thanks for the link. I wish I knew what it all meant! However, I've unticked the preview pane as suggested in the latest posts. I'll see what happens.

Success, so far!! Having unticked the preview pane I have deleted the earlier 9 versions of my document. I have also opened version 10 a few times, and it hasn't changed to 'read only'. Let's hope it stays that way! Thanks very much for your help.