If this is happening to you in two different applications (Word & Access), then I don't think it would be an Access issue. Maybe try to repair your Office install and see if that helps? Or check your Office security settings to make sure that it's not a security feature that's blocking your tabs? Perhaps office is blocking any files of yours that have macros attached?
I don't think you'll need to migrate your databases to Access 2010. Before you try that I would try compact&repair to see if that fixes it. Maybe also try opening it with the shift key down to disable any startup processes in the database. Maybe also try to turn off some security features in your Access database if any are enabled.
In my experience, MS Access backward compatibility means that if your older Access database only has standard MS Access components -- just tables, queries, forms, reports, and probably macros as well (but don't quote me on that) -- you should be able to open it and use it in a newer version of Access. On the other hand, if you have any custom modules attached, you might need to restore/include some older libraries in VBA to get your code working again.
P.S. I don't have enough points to comment, so I'll add here my response to your question, "I have a front end accdb file(in access 2007) and back end mdb file(in access 2000). Can i make it work in access 2013?" I don't see any reason why this wouldn't work other than what I've already written above. If you do run into an issue, though, you can try (A) converting your Access 2007 front end to Access 2013, or if that doesn't work (B) importing the objects from your Access 2007 front end into a new Access 2013 database, or in the worst case (C) import the objects from your Access 2007 front end into a new Access 2013 database one by one until you find out which one might be giving you the issue.
