Is it a trial version of Word 2010, (Office 2010), that came pre-installed on your computer or that you have downloaded from Microsoft?
If it is the full retail version, is this problem the same with all documents, or just this particular one?
Have you tried different ways to open this document in Word; eg, double clicking the file itself, or open Word, then goto File > Open, navigate to where the file is and selecting it? (I know Word 2010 now has the ribbon menu options, but I still refer to them by the older method).
What happens when you try both?
I have Office 2007 on my work pc (running XP), and Office 2010 on my home pc (running Windows 7). I took one of my Word docs (saved in 2007), and opened it on the home pc in Word 2010.
I did my changes, and then clicked save. I could see that the document was saved in Compatibility Mode - as the name on the top tool bar was "Doc Name" (Compatibility Mode).
Document saved all ok - no problems. File size was reduced from 1500 KB to 500 KB at the point of saving the file, though.
I then tried to open the file on my work pc in Word 2007. Nothing happens. Word opens, but the actual document does not. I only have the option for "New" and "Open", and everything else is greyed out.
Anyone have any idea what this issue is? I have the compatibility pack for 2007 installed on my pc.