Excel 2010 can't open .xlsx files

Wolf used Ask the Experts™
I've upgrade office 2007 to office 2010

After the upgrade i am unable to open any .xlsx files using excel

I have a number of .xlsx files on my desktop and windows doesn't know which program to use to open them.  If i open excel first and go to open and then point to the files, they open fine, just not when i double click on the files directly.

If i create and save a new excel spreadsheet in the default settings as .xlsx it saves it fine but then doesn't know which program to open it in.

This is only happening in Excel, Word files are fine.

I'm using Windows 7

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Expert Office
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Yeah, it looks like you lost the "file associations" during the uninstall/reinstall
Here is an article on how to fix this:  http://support.microsoft.com/kb/307859
Specifically, Excel 2010 uses:   "C:\Program Files\Microsoft Office\Office 14\Excel.exe" /dde
TracyVBA Developer

To change the file association, try this:

Open Control Panel > Control Panel Home > Default Programs >  Set Associations. Select the Excel file type in the list and click Change  Program, then select Excel 2010.


When i go to control panel > default programs i find xlsx and it says Unknown program.  So i then click Change program and it comes up with the Open with dialog box
Excel isn't listed so i go into Browse, and navigate to the excel.exe and click open.  However, nothing then happens, it just goes back to the open with dialog box and excel isn't listed
Any ideas?
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TracyVBA Developer

You could try to do a repair on Office.  Something may have been messed up during installation.  

I'd suggest doing the repair, then rebooting, and then trying to reset the file association.


I've tried doing a repair on Office 2010, installing all the latest updates, and rebootings - it hasn't fixed it.
When i trying to chose the file association it will show word, access, visio 2010 etc but doesn't show Excel as an option.  When i try to browse to it, it just doesn't do anything.
I completely removed Office 2007, rebooted, and then installed Office 2010 from scratch
It's the 64 Bit edition
Any other ideas?
TracyVBA Developer
Can you try recreating the profile, it may have gotten corrupted.  You could also try logging on as a different user first, to see if works under a different profile.

did you try the string that I provided (with the /dde at the end)?
"C:\Program Files\Microsoft Office\Office 14\Excel.exe" /dde
Note: change the path to whatever your install path is...
If you are comfortable about editing the registry, you might want copy-n-paste the attached into a file (with a *.reg extension), and then just double-click on it to install it.  I exported this from the registry on my Win7 / Office 2010 PC.

Windows Registry Editor Version 5.00

"Content Type"="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"








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When i logged in as a different user it worked fine, so it was my profile but i really didn't want to recreat my profile

I ran the reg fix and after a reboot it would now let me choose excel as an option to open .xlsx files which is great!

Thanks very much for the help :)

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