Excel 2007: “There was a problem sending the command to the program”

There are following steps for resolution this types of error.

Step 1: Open Excel
Step 2: Open the Menu in the top left
Step 3: Click on the "Excel Option" button

Step 4: Click the advanced tab on the left of the options screen
Step 5:  Uncheck the box “Ignore other application that use Dynamic Data Exchange (DDE)”
Step 6: Click on Ok button and then try to open your excel files.