1) Open microsoft Excel (any version), then go to options -> advance (in Excel 2010)
2) Find a checkbox saying: "Ignore Other Application" or "Ignore Other Application that use DDE" (in Excel 2010).Make sure you unchecked it. If you cant find it under the advanced tab, just search around, it should be somewhere in the options, depending on which version of Excel you have. Save it.
3) Try to directly open document by double clicking it. Should be fine now.
