IF YOU ARE RUNNING WIN 7 64 bit .... After 2 hours with MS on the phone, I have a solution!!!!
The directions are wordy, but I am not a geek, and I have had to learn how to help my 80 yr old mother troubleshoot things at her house when she is 2 hrs away and we are on the phone or I am sending her an email. If you are geeky, just skip the parts you know.
RIGHT click on your old file that you want to open in Office 2010.
A menu pops out. Move your mouse to OPEN WITH
Click on CHOOSE DEFAULT PROGRAM
A pop up window appears,
CHECK MARK the "Always use the selected program to open this kind of file"
Click BROWSE
A window / pop up menu appears, LOOK at the line at the top where it says "Computer > (C:) > Program Files > "
LEFT CLICK on (C:)
The window / pop up menu now reads "Computer > (C:) >"
DOUBLE LEFT CLICK on "PROGRAM FILES (x86)"
Scroll down to "Microsoft Office" and DOUBLE LEFT CLICK it
DOUBLE LEFT CLICK "Office14" (NOT *"Options14"*BUT "Office14")
Scroll down until you find the program you need
For Word WINWORD
For Excel EXCEL
For PowerPoint POWERPNT
For OneNote ONENOTE (if this does not work try ONENOTEM)
For Outlook OUTLOOK
For Publisher MSPUB
For Access MSACCESS
SINGLE LEFT CLICK the program you want, than click OK at the bottom of the Menu
This will take you back to the *"Choose the program you want to use to open this file:"*Menu and the file type you have chosen will now be on the list. Make sure that you have clicked the "Always use the selected program to open this kind of file Box!!!!SINGLE LEFT CLICK on the program you want to use and then click
OK at the bottom of the menu / pop up
The program will begin to open but you will get a pop up message. It will say something similar to "the file you are trying to open 'file name' is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a trusted source before opening the file. Do you want to open the file now?" Click
YES
Your file should now open in the correct format.
IMMEDIATELY after you open the file, SINGLE LEFT CLICK the "File" tab in the upper right corner of your screen
DOUBLE LEFT CLICK "Save as"
A new Menu / Pop up appears. You will have to type in the name of the file where it asks
"File name:" (You can use the same file name as the OLD file.)
SINGLE LEFT CLICK AND HOLD the little arrow at the right end of the box marked *"Save as type:"*and make sure that the highlighted choice is whatever the First/Top choice is. That will be the latest version available (2010) If it is
RELEASE your left Mouse Button closing the drop down portion of this menu.
SINGLE LEFT CLICK "Save"
You are done. Now every time you open that kind of file you should not have to repeat this process. Otherwise just repeat these steps.
BY THE WAY: The "Program Files" folder vs. the "Program Files (x86)" folder problem was discovered quite by accident when I had the MS Tech on the phone (and computer sharing) with me. So this problem / solution is now known to at least
one of the Office 2010 Technical Support folks over on the other side of the earth where they live. I asked him to let others know. Maybe he will.