I have a user who opens 4 or 5 Excel files at a time. She does this by clicking on the file's icon to launch Excel, rather than going to File | Open. After launching multiple instances of Excel.exe, she can no longer open additional files probably due to memory. My question is: Is there a way to get these files to open within the same excel.exe instance, rather than starting up a new Excel window each time a file is double-clicked?