The OS is Windows XP and the program is Microsoft Office Standard 2007 (Excel). This computer recently upgraded from Office 2003 to Office 2007 (Yeah, I know don't shoot me).
Upon clicking any .xls or .xlsx file Excel 2007 will open and stop there. The file itself will not open traditionally. The workaround thus far is to then go into the menu and select Open and select the file that way, then the file opens. Microsoft Word does not have this same issue; the files open correctly.
The .xls and .xlsx files are already associated with Microsoft Excel 2007. Any help is appreciated.
Best Answer
Go to http://support.microsoft.com/kb/211494 and it will give a very clear explanation of how to make it so Excel opens the file. I searched on: "Excel 2007 'There was a problem sending the command to the program'" since that was the error message.
Open the Excel application. Here are Microsoft's instructions from that link - very simple to follow!
Microsoft Excel 2010
Microsoft Office Excel 2007
Microsoft Office Excel 2003 or earlier versions of Excel
Even if the option Ignore other aplications that use Dynamic Data Exchange (DDE) is already clear (false), click to enable and then click to disable.
After you do this, you should be able to open workbooks by double-clicking them in Windows Explorer.