Excel for mac keeps locking my documents and I can't access

HELP!! All my Excel files are now marked as "read only" and won't open. I did not do this, and they come with a read only document, and I cannot figure out what to do. I have updated, restarted the macbook, powered off the macbook, etc, all to no avail.
Any suggestion are appreciated!
Thanks so much...


It looks like you have Office 2004, which doesn't run on Mountain Lion. Upgrade to Office 2008 or 2011.