Help With Missing EXE File Association

So today, I opened Outlook and downloaded my email messages. Every single day, I get a report from one of my staff in Excel and today – for no reason I can think of – I cannot open the Excel file attachment. Since I’m a bit ‘techie’ I was already thinking that I probably have to reset an exe file association on my Windows registry.

Most programs or documents can only be opened or used if your operating system knows how to launch it. In the example above, the Excel document had a *.xlsx extension, which meant that Excel 2007 is required to open it.

To be more precise, Excel.exe is required to open the *.xlsx worksheet that was sent to me and for some reason that did not work anymore, so here’s what I did to troubleshoot this problem.

1)   Check that it’s not just that particular file that has the problem. Before I went and fiddled with file associations and the Windows registry, I wanted to make sure it was a general problem and not just because that attachment got corrupted or infected with a virus. So I downloaded the file, ran a virus check on it and double-clicked it. That did not work.

Furthermore, when I tried to open Excel reports from previous days, which I could open before, they would not launch either. So I was sure at this point that it was more an incorrect or missing file association issue.

2)   Next, modify the Dynamic Data Exchange (DDE) settings in Excel. Based on what I saw on some Excel forums, I tried to do the following.

• Close the e-mail message.
• Open MS Excel.
• Click the Microsoft Office Button, go to Options, and then click Advanced.
• Select the General tab and then clear or un-check the option Ignore other applications that use Dynamic Data Exchange (DDE)
• Click OK.
• Close MS Excel.

For added measure, I even rebooted my PC after this but this did not work for me either!

3)   By now it was obvious that there was an exe file association missing in relation to Excel. So here’s what I did. (Mind you: always back up your Windows registry before you make any changes!)

• From the Windows Start menu, click Run.
• Type regedit and then click OK. This will open the Registry Editor.
• Now go to this location:

HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\FileExts\.xlsx

(or whatever the file extension you are having problem with)

• Click the OpenWithList folder.
• Right-click a and then select Modify.
• Under Value Data, indicate the EXE or program that should be used to open the document you want.
• Click OK and then exit the Windows Registry.

After the above I restarted my PC and the problem was solved!